Commit Graph

2432 Commits

Author SHA1 Message Date
Nishanth Aravamudan 5e9426abe2 mm: remove mm_init compilation dependency on CONFIG_DEBUG_MEMORY_INIT
Towards the end of putting all core mm initialization in mm_init.c, I
plan on putting the creation of a mm kobject in a function in that file.
However, the file is currently only compiled if CONFIG_DEBUG_MEMORY_INIT
is set. Remove this dependency, but put the code under an #ifdef on the
same config option. This should result in no functional changes.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:17 -07:00
Eric Dumazet a47a126ad5 vmallocinfo: add NUMA information
Christoph recently added /proc/vmallocinfo file to get information about
vmalloc allocations.

This patch adds NUMA specific information, giving number of pages
allocated on each memory node.

This should help to check that vmalloc() is able to respect NUMA policies.

Example of output on a four nodes machine (one cpu per node)

1) network hash tables are evenly spreaded on four nodes (OK) (Same
   point for inodes and dentries hash tables)

2) iptables tables (x_tables) are correctly allocated on each cpu node
   (OK).

3) sys_swapon() allocates its memory from one node only.

4) each loaded module is using memory on one node.

Sysadmins could tune their setup to change points 3) and 4) if necessary.

grep "pages="  /proc/vmallocinfo
0xffffc20000000000-0xffffc20000201000 2101248 alloc_large_system_hash+0x204/0x2c0 pages=512 vmalloc N0=128 N1=128 N2=128 N3=128
0xffffc20000201000-0xffffc20000302000 1052672 alloc_large_system_hash+0x204/0x2c0 pages=256 vmalloc N0=64 N1=64 N2=64 N3=64
0xffffc2000031a000-0xffffc2000031d000   12288 alloc_large_system_hash+0x204/0x2c0 pages=2 vmalloc N1=1 N2=1
0xffffc2000031f000-0xffffc2000032b000   49152 cramfs_uncompress_init+0x2e/0x80 pages=11 vmalloc N0=3 N1=3 N2=2 N3=3
0xffffc2000033e000-0xffffc20000341000   12288 sys_swapon+0x640/0xac0 pages=2 vmalloc N0=2
0xffffc20000341000-0xffffc20000344000   12288 xt_alloc_table_info+0xfe/0x130 [x_tables] pages=2 vmalloc N0=2
0xffffc20000344000-0xffffc20000347000   12288 xt_alloc_table_info+0xfe/0x130 [x_tables] pages=2 vmalloc N1=2
0xffffc20000347000-0xffffc2000034a000   12288 xt_alloc_table_info+0xfe/0x130 [x_tables] pages=2 vmalloc N2=2
0xffffc2000034a000-0xffffc2000034d000   12288 xt_alloc_table_info+0xfe/0x130 [x_tables] pages=2 vmalloc N3=2
0xffffc20004381000-0xffffc20004402000  528384 alloc_large_system_hash+0x204/0x2c0 pages=128 vmalloc N0=32 N1=32 N2=32 N3=32
0xffffc20004402000-0xffffc20004803000 4198400 alloc_large_system_hash+0x204/0x2c0 pages=1024 vmalloc vpages N0=256 N1=256 N2=256 N3=256
0xffffc20004803000-0xffffc20004904000 1052672 alloc_large_system_hash+0x204/0x2c0 pages=256 vmalloc N0=64 N1=64 N2=64 N3=64
0xffffc20004904000-0xffffc20004bec000 3047424 sys_swapon+0x640/0xac0 pages=743 vmalloc vpages N0=743
0xffffffffa0000000-0xffffffffa000f000   61440 sys_init_module+0xc27/0x1d00 pages=14 vmalloc N1=14
0xffffffffa000f000-0xffffffffa0014000   20480 sys_init_module+0xc27/0x1d00 pages=4 vmalloc N0=4
0xffffffffa0014000-0xffffffffa0017000   12288 sys_init_module+0xc27/0x1d00 pages=2 vmalloc N0=2
0xffffffffa0017000-0xffffffffa0022000   45056 sys_init_module+0xc27/0x1d00 pages=10 vmalloc N1=10
0xffffffffa0022000-0xffffffffa0028000   24576 sys_init_module+0xc27/0x1d00 pages=5 vmalloc N3=5
0xffffffffa0028000-0xffffffffa0050000  163840 sys_init_module+0xc27/0x1d00 pages=39 vmalloc N1=39
0xffffffffa0050000-0xffffffffa0052000    8192 sys_init_module+0xc27/0x1d00 pages=1 vmalloc N1=1
0xffffffffa0052000-0xffffffffa0056000   16384 sys_init_module+0xc27/0x1d00 pages=3 vmalloc N1=3
0xffffffffa0056000-0xffffffffa0081000  176128 sys_init_module+0xc27/0x1d00 pages=42 vmalloc N3=42
0xffffffffa0081000-0xffffffffa00ae000  184320 sys_init_module+0xc27/0x1d00 pages=44 vmalloc N3=44
0xffffffffa00ae000-0xffffffffa00b1000   12288 sys_init_module+0xc27/0x1d00 pages=2 vmalloc N3=2
0xffffffffa00b1000-0xffffffffa00b9000   32768 sys_init_module+0xc27/0x1d00 pages=7 vmalloc N0=7
0xffffffffa00b9000-0xffffffffa00c4000   45056 sys_init_module+0xc27/0x1d00 pages=10 vmalloc N3=10
0xffffffffa00c6000-0xffffffffa00e0000  106496 sys_init_module+0xc27/0x1d00 pages=25 vmalloc N2=25
0xffffffffa00e0000-0xffffffffa00f1000   69632 sys_init_module+0xc27/0x1d00 pages=16 vmalloc N2=16
0xffffffffa00f1000-0xffffffffa00f4000   12288 sys_init_module+0xc27/0x1d00 pages=2 vmalloc N3=2
0xffffffffa00f4000-0xffffffffa00f7000   12288 sys_init_module+0xc27/0x1d00 pages=2 vmalloc N3=2

[akpm@linux-foundation.org: fix comment]
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:17 -07:00
Hugh Dickins bcd78e4961 tmpfs: support aio
We have a request for tmpfs to support the AIO interface: easily done, no
more than replacing the old shmem_file_read by shmem_file_aio_read,
cribbed from generic_file_aio_read.  (In 2.6.25 its write side was already
changed to use generic_file_aio_write.)

Incorporate cleanups from Andrew Morton and Harvey Harrison.

Tests out fine with LTP's ltp-aiodio.sh, given hacks (not included) to
support O_DIRECT.  tmpfs cannot honestly support O_DIRECT: its
cache-avoiding-IO nature is at odds with direct IO-avoiding-cache.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Tested-by: Lawrence Greenfield <leg@google.com>
Cc: Christoph Rohland <hans-christoph.rohland@sap.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Zach Brown <zach.brown@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:16 -07:00
Hugh Dickins 11fa977ecd generic_file_aio_read() cleanups
As akpm points out, there's really no need for generic_file_aio_read to
make a special case of count 0: just loop through nr_segs doing nothing.
And as Harvey Harrison points out, there's no need to reset retval to 0
where it's already 0.

Setting count (or ocount) to 0 before calling generic_segment_checks is
unnecessary too; but reluctantly I'll leave that removal to someone with a
wider range of gcc versions to hand - 4.1.2 and 4.2.1 don't warn about it,
but perhaps others do - I forget which are the warniest versions.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Tested-by: Lawrence Greenfield <leg@google.com>
Cc: Christoph Rohland <hans-christoph.rohland@sap.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:16 -07:00
Johannes Weiner a858f7b2e9 vma_page_offset() has no callees: drop it
Hugh adds: vma_pagecache_offset() has a dangerously misleading name, since
it's using hugepage units: rename it to vma_hugecache_offset().

[apw@shadowen.org: restack onto fixed MAP_PRIVATE reservations]
[akpm@linux-foundation.org: vma_split conversion]
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:16 -07:00
Andy Whitcroft 84afd99b83 hugetlb reservations: fix hugetlb MAP_PRIVATE reservations across vma splits
When a hugetlb mapping with a reservation is split, a new VMA is cloned
from the original.  This new VMA is a direct copy of the original
including the reservation count.  When this pair of VMAs are unmapped we
will incorrect double account the unused reservation and the overall
reservation count will be incorrect, in extreme cases it will wrap.

The problem occurs when we split an existing VMA say to unmap a page in
the middle.  split_vma() will create a new VMA copying all fields from the
original.  As we are storing our reservation count in vm_private_data this
is also copies, endowing the new VMA with a duplicate of the original
VMA's reservation.  Neither of the new VMAs can exhaust these reservations
as they are too small, but when we unmap and close these VMAs we will
incorrect credit the remainder twice and resv_huge_pages will become out
of sync.  This can lead to allocation failures on mappings with
reservations and even to resv_huge_pages wrapping which prevents all
subsequent hugepage allocations.

The simple fix would be to correctly apportion the remaining reservation
count when the split is made.  However the only hook we have vm_ops->open
only has the new VMA we do not know the identity of the preceeding VMA.
Also even if we did have that VMA to hand we do not know how much of the
reservation was consumed each side of the split.

This patch therefore takes a different tack.  We know that the whole of
any private mapping (which has a reservation) has a reservation over its
whole size.  Any present pages represent consumed reservation.  Therefore
if we track the instantiated pages we can calculate the remaining
reservation.

This patch reuses the existing regions code to track the regions for which
we have consumed reservation (ie.  the instantiated pages), as each page
is faulted in we record the consumption of reservation for the new page.
When we need to return unused reservations at unmap time we simply count
the consumed reservation region subtracting that from the whole of the
map.  During a VMA split the newly opened VMA will point to the same
region map, as this map is offset oriented it remains valid for both of
the split VMAs.  This map is referenced counted so that it is removed when
all VMAs which are part of the mmap are gone.

Thanks to Adam Litke and Mel Gorman for their review feedback.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Johannes Weiner <hannes@saeurebad.de>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Jon Tollefson <kniht@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:16 -07:00
Andy Whitcroft c37f9fb11c hugetlb: allow huge page mappings to be created without reservations
By default all shared mappings and most private mappings now have
reservations associated with them.  This improves semantics by providing
allocation guarentees to the mapper.  However a small number of
applications may attempt to make very large sparse mappings, with these
strict reservations the system will never be able to honour the mapping.

This patch set brings MAP_NORESERVE support to hugetlb files.  This allows
new mappings to be made to hugetlbfs files without an associated
reservation, for both shared and private mappings.  This allows
applications which want to create very sparse mappings to opt-out of the
reservation system.  Obviously as there is no reservation they are liable
to fault at runtime if the huge page pool becomes exhausted; buyer beware.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Johannes Weiner <hannes@saeurebad.de>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:16 -07:00
Andy Whitcroft 9682290484 hugetlb: move reservation region support earlier
The following patch will require use of the reservation regions support.
Move this earlier in the file.  No changes have been made to this code.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Adam Litke <agl@us.ibm.com>
Cc: Johannes Weiner <hannes@saeurebad.de>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:16 -07:00
Andy Whitcroft cdfd4325c0 mm: record MAP_NORESERVE status on vmas and fix small page mprotect reservations
With Mel's hugetlb private reservation support patches applied, strict
overcommit semantics are applied to both shared and private huge page
mappings.  This can be a problem if an application relied on unlimited
overcommit semantics for private mappings.  An example of this would be an
application which maps a huge area with the intention of using it very
sparsely.  These application would benefit from being able to opt-out of
the strict overcommit.  It should be noted that prior to hugetlb
supporting demand faulting all mappings were fully populated and so
applications of this type should be rare.

This patch stack implements the MAP_NORESERVE mmap() flag for huge page
mappings.  This flag has the same meaning as for small page mappings,
suppressing reservations for that mapping.

Thanks to Mel Gorman for reviewing a number of early versions of these
patches.

This patch:

When a small page mapping is created with mmap() reservations are created
by default for any memory pages required.  When the region is read/write
the reservation is increased for every page, no reservation is needed for
read-only regions (as they implicitly share the zero page).  Reservations
are tracked via the VM_ACCOUNT vma flag which is present when the region
has reservation backing it.  When we convert a region from read-only to
read-write new reservations are aquired and VM_ACCOUNT is set.  However,
when a read-only map is created with MAP_NORESERVE it is indistinguishable
from a normal mapping.  When we then convert that to read/write we are
forced to incorrectly create reservations for it as we have no record of
the original MAP_NORESERVE.

This patch introduces a new vma flag VM_NORESERVE which records the
presence of the original MAP_NORESERVE flag.  This allows us to
distinguish these two circumstances and correctly account the reserve.

As well as fixing this FIXME in the code, this makes it much easier to
introduce MAP_NORESERVE support for huge pages as this flag is available
consistantly for the life of the mapping.  VM_ACCOUNT on the other hand is
heavily used at the generic level in association with small pages.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Johannes Weiner <hannes@saeurebad.de>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:16 -07:00
Andy Whitcroft e7c4b0bfd0 huge page private reservation review cleanups
Create some new accessors for vma private data to cut down on and contain
the casts.  Encapsulates the huge and small page offset calculations.
Also adds a couple of VM_BUG_ONs for consistency.

[akpm@linux-foundation.org: Make things static]
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Johannes Weiner <hannes@saeurebad.de>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:16 -07:00
Mel Gorman 04f2cbe356 hugetlb: guarantee that COW faults for a process that called mmap(MAP_PRIVATE) on hugetlbfs will succeed
After patch 2 in this series, a process that successfully calls mmap() for
a MAP_PRIVATE mapping will be guaranteed to successfully fault until a
process calls fork().  At that point, the next write fault from the parent
could fail due to COW if the child still has a reference.

We only reserve pages for the parent but a copy must be made to avoid
leaking data from the parent to the child after fork().  Reserves could be
taken for both parent and child at fork time to guarantee faults but if
the mapping is large it is highly likely we will not have sufficient pages
for the reservation, and it is common to fork only to exec() immediatly
after.  A failure here would be very undesirable.

Note that the current behaviour of mainline with MAP_PRIVATE pages is
pretty bad.  The following situation is allowed to occur today.

1. Process calls mmap(MAP_PRIVATE)
2. Process calls mlock() to fault all pages and makes sure it succeeds
3. Process forks()
4. Process writes to MAP_PRIVATE mapping while child still exists
5. If the COW fails at this point, the process gets SIGKILLed even though it
   had taken care to ensure the pages existed

This patch improves the situation by guaranteeing the reliability of the
process that successfully calls mmap().  When the parent performs COW, it
will try to satisfy the allocation without using reserves.  If that fails
the parent will steal the page leaving any children without a page.
Faults from the child after that point will result in failure.  If the
child COW happens first, an attempt will be made to allocate the page
without reserves and the child will get SIGKILLed on failure.

To summarise the new behaviour:

1. If the original mapper performs COW on a private mapping with multiple
   references, it will attempt to allocate a hugepage from the pool or
   the buddy allocator without using the existing reserves. On fail, VMAs
   mapping the same area are traversed and the page being COW'd is unmapped
   where found. It will then steal the original page as the last mapper in
   the normal way.

2. The VMAs the pages were unmapped from are flagged to note that pages
   with data no longer exist. Future no-page faults on those VMAs will
   terminate the process as otherwise it would appear that data was corrupted.
   A warning is printed to the console that this situation occured.

2. If the child performs COW first, it will attempt to satisfy the COW
   from the pool if there are enough pages or via the buddy allocator if
   overcommit is allowed and the buddy allocator can satisfy the request. If
   it fails, the child will be killed.

If the pool is large enough, existing applications will not notice that
the reserves were a factor.  Existing applications depending on the
no-reserves been set are unlikely to exist as for much of the history of
hugetlbfs, pages were prefaulted at mmap(), allocating the pages at that
point or failing the mmap().

[npiggin@suse.de: fix CONFIG_HUGETLB=n build]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Adam Litke <agl@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:16 -07:00
Mel Gorman a1e78772d7 hugetlb: reserve huge pages for reliable MAP_PRIVATE hugetlbfs mappings until fork()
This patch reserves huge pages at mmap() time for MAP_PRIVATE mappings in
a similar manner to the reservations taken for MAP_SHARED mappings.  The
reserve count is accounted both globally and on a per-VMA basis for
private mappings.  This guarantees that a process that successfully calls
mmap() will successfully fault all pages in the future unless fork() is
called.

The characteristics of private mappings of hugetlbfs files behaviour after
this patch are;

1. The process calling mmap() is guaranteed to succeed all future faults until
   it forks().
2. On fork(), the parent may die due to SIGKILL on writes to the private
   mapping if enough pages are not available for the COW. For reasonably
   reliable behaviour in the face of a small huge page pool, children of
   hugepage-aware processes should not reference the mappings; such as
   might occur when fork()ing to exec().
3. On fork(), the child VMAs inherit no reserves. Reads on pages already
   faulted by the parent will succeed. Successful writes will depend on enough
   huge pages being free in the pool.
4. Quotas of the hugetlbfs mount are checked at reserve time for the mapper
   and at fault time otherwise.

Before this patch, all reads or writes in the child potentially needs page
allocations that can later lead to the death of the parent.  This applies
to reads and writes of uninstantiated pages as well as COW.  After the
patch it is only a write to an instantiated page that causes problems.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Adam Litke <agl@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:16 -07:00
Mel Gorman fc1b8a73dd hugetlb: move hugetlb_acct_memory()
This is a patchset to give reliable behaviour to a process that
successfully calls mmap(MAP_PRIVATE) on a hugetlbfs file.  Currently, it
is possible for the process to be killed due to a small hugepage pool size
even if it calls mlock().

MAP_SHARED mappings on hugetlbfs reserve huge pages at mmap() time.  This
guarantees all future faults against the mapping will succeed.  This
allows local allocations at first use improving NUMA locality whilst
retaining reliability.

MAP_PRIVATE mappings do not reserve pages.  This can result in an
application being SIGKILLed later if a huge page is not available at fault
time.  This makes huge pages usage very ill-advised in some cases as the
unexpected application failure cannot be detected and handled as it is
immediately fatal.  Although an application may force instantiation of the
pages using mlock(), this may lead to poor memory placement and the
process may still be killed when performing COW.

This patchset introduces a reliability guarantee for the process which
creates a private mapping, i.e.  the process that calls mmap() on a
hugetlbfs file successfully.  The first patch of the set is purely
mechanical code move to make later diffs easier to read.  The second patch
will guarantee faults up until the process calls fork().  After patch two,
as long as the child keeps the mappings, the parent is no longer
guaranteed to be reliable.  Patch 3 guarantees that the parent will always
successfully COW by unmapping the pages from the child in the event there
are insufficient pages in the hugepage pool in allocate a new page, be it
via a static or dynamic pool.

Existing hugepage-aware applications are unlikely to be affected by this
change.  For much of hugetlbfs's history, pages were pre-faulted at mmap()
time or mmap() failed which acts in a reserve-like manner.  If the pool is
sized correctly already so that parent and child can fault reliably, the
application will not even notice the reserves.  It's only when the pool is
too small for the application to function perfectly reliably that the
reserves come into play.

Credit goes to Andy Whitcroft for cleaning up a number of mistakes during
review before the patches were released.

This patch:

A later patch in this set needs to call hugetlb_acct_memory() before it is
defined.  This patch moves the function without modification.  This makes
later diffs easier to read.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Adam Litke <agl@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:16 -07:00
Johannes Weiner 9109fb7b35 mm: drop unneeded pgdat argument from free_area_init_node()
free_area_init_node() gets passed in the node id as well as the node
descriptor.  This is redundant as the function can trivially get the node
descriptor itself by means of NODE_DATA() and the node's id.

I checked all the users and NODE_DATA() seems to be usable everywhere
from where this function is called.

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:16 -07:00
Andy Whitcroft 9023cb7e85 slob: record page flag overlays explicitly
SLOB reuses two page bits for internal purposes, it overlays PG_active and
PG_private.  This is hidden away in slob.c.  Document these overlays
explicitly in the main page-flags enum along with all the others.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:15 -07:00
Andy Whitcroft 8a38082d21 slub: record page flag overlays explicitly
SLUB reuses two page bits for internal purposes, it overlays PG_active and
PG_error.  This is hidden away in slub.c.  Document these overlays
explicitly in the main page-flags enum along with all the others.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:15 -07:00
Andy Whitcroft 3c82d0ce2c buddy: clarify comments describing buddy merge
In __free_one_page(), the comment "Move the buddy up one level" appears
attached to the break and by implication when the break is taken we are
moving it up one level:

	if (!page_is_buddy(page, buddy, order))
		break;          /* Move the buddy up one level. */

In reality the inverse is true, we break out when we can no longer merge
this page with its buddy.  Looking back into pre-history (into the full
git history) it appears that these two lines accidentally got joined as
part of another change.

Move the comment down where it belongs below the if and clarify its
language.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:15 -07:00
Jan Beulich 42b7772812 mm: remove double indirection on tlb parameter to free_pgd_range() & Co
The double indirection here is not needed anywhere and hence (at least)
confusing.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:15 -07:00
Rik van Riel 28b2ee20c7 access_process_vm device memory infrastructure
In order to be able to debug things like the X server and programs using
the PPC Cell SPUs, the debugger needs to be able to access device memory
through ptrace and /proc/pid/mem.

This patch:

Add the generic_access_phys access function and put the hooks in place
to allow access_process_vm to access device or PPC Cell SPU memory.

[riel@redhat.com: Add documentation for the vm_ops->access function]
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Benjamin Herrensmidt <benh@kernel.crashing.org>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:15 -07:00
Nick Piggin 0d71d10a42 mm: remove nopfn
There are no users of nopfn in the tree. Remove it.

[hugh@veritas.com: fix build error]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:15 -07:00
Christoph Hellwig a969e903a9 kill generic_file_direct_IO()
generic_file_direct_IO is a common helper around the invocation of
->direct_IO.  But there's almost nothing shared between the read and write
side, so we're better off without this helper.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:14 -07:00
Adrian Bunk 75353bed36 mm/hugetlb.c: fix duplicate variable
It's confusing that set_max_huge_pages() contained two different
variables named "ret", and although the code works correctly this should
be fixed.

The inner of the two variables can simply be removed.

Spotted by sparse.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc:  "KOSAKI Motohiro" <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:14 -07:00
Adrian Bunk c748e1340e mm/vmstat.c: proper externs
This patch adds proper extern declarations for five variables in
include/linux/vmstat.h

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:14 -07:00
Adrian Bunk 4f5ca26578 mm/migrate.c should #include <linux/syscalls.h>
Every file should include the headers containing the externs for its
global functions (in this case for sys_move_pages()).

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:14 -07:00
KOSAKI Motohiro e4048e5dc4 page allocator: inline some __alloc_pages() wrappers
Two zonelist patch series rewrote __page_alloc() largely.  Now, it is just
a wrapper function.  Inlining them will save a function call.

[akpm@linux-foundation.org: export __alloc_pages_internal]
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:14 -07:00
Johannes Weiner ffc6421f07 mm: unexport __alloc_bootmem_core()
This function has no external callers, so unexport it.  Also fix its naming
inconsistency.

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:14 -07:00
Johannes Weiner 8ae0446307 mm: normalize internal argument passing of bootmem data
All _core functions only need the bootmem data, not the whole node descriptor.
Adjust the two functions that take the node descriptor unneededly.

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:14 -07:00
Johannes Weiner 6b312c0e6e mm: fix free_all_bootmem_core alignment check
The check for node_boot_start is bogus because we start freeing at the
corresponding pfn.  So check if the pfn is properly aligned instead in a more
readable way and adjust the documentation.

Also remove an unneeded accounting variable.

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:14 -07:00
Johannes Weiner b61bfa3c46 mm: move bootmem descriptors definition to a single place
There are a lot of places that define either a single bootmem descriptor or an
array of them.  Use only one central array with MAX_NUMNODES items instead.

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:14 -07:00
Mel Gorman 68ad8df42e mm: print out the zonelists on request for manual verification
This patch prints out the zonelists during boot for manual verification by the
user if the mminit_loglevel is MMINIT_VERIFY or higher.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:14 -07:00
Mel Gorman 2dbb51c49f mm: make defensive checks around PFN values registered for memory usage
There are a number of different views to how much memory is currently active.
There is the arch-independent zone-sizing view, the bootmem allocator and
memory models view.

Architectures register this information at different times and is not
necessarily in sync particularly with respect to some SPARSEMEM limitations.

This patch introduces mminit_validate_memmodel_limits() which is able to
validate and correct PFN ranges with respect to the memory model.  It is only
SPARSEMEM that currently validates itself.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:13 -07:00
Mel Gorman 708614e618 mm: verify the page links and memory model
Print out information on how the page flags are being used if mminit_loglevel
is MMINIT_VERIFY or higher and unconditionally performs sanity checks on the
flags regardless of loglevel.

When the page flags are updated with section, node and zone information, a
check are made to ensure the values can be retrieved correctly.  Finally we
confirm that pfn_to_page and page_to_pfn are the correct inverse functions.

[akpm@linux-foundation.org: fix printk warnings]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:13 -07:00
Mel Gorman 6b74ab97bc mm: add a basic debugging framework for memory initialisation
Boot initialisation is very complex, with significant numbers of
architecture-specific routines, hooks and code ordering.  While significant
amounts of the initialisation is architecture-independent, it trusts the data
received from the architecture layer.  This is a mistake, and has resulted in
a number of difficult-to-diagnose bugs.

This patchset adds some validation and tracing to memory initialisation.  It
also introduces a few basic defensive measures.  The validation code can be
explicitly disabled for embedded systems.

This patch:

Add additional debugging and verification code for memory initialisation.

Once enabled, the verification checks are always run and when required
additional debugging information may be outputted via a mminit_loglevel=
command-line parameter.

The verification code is placed in a new file mm/mm_init.c.  Ideally other mm
initialisation code will be moved here over time.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:13 -07:00
Linus Torvalds 26dcce0fab Merge branch 'cpus4096-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'cpus4096-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (31 commits)
  NR_CPUS: Replace NR_CPUS in speedstep-centrino.c
  cpumask: Provide a generic set of CPUMASK_ALLOC macros, FIXUP
  NR_CPUS: Replace NR_CPUS in cpufreq userspace routines
  NR_CPUS: Replace per_cpu(..., smp_processor_id()) with __get_cpu_var
  NR_CPUS: Replace NR_CPUS in arch/x86/kernel/genapic_flat_64.c
  NR_CPUS: Replace NR_CPUS in arch/x86/kernel/genx2apic_uv_x.c
  NR_CPUS: Replace NR_CPUS in arch/x86/kernel/cpu/proc.c
  NR_CPUS: Replace NR_CPUS in arch/x86/kernel/cpu/mcheck/mce_64.c
  cpumask: Optimize cpumask_of_cpu in lib/smp_processor_id.c, fix
  cpumask: Use optimized CPUMASK_ALLOC macros in the centrino_target
  cpumask: Provide a generic set of CPUMASK_ALLOC macros
  cpumask: Optimize cpumask_of_cpu in lib/smp_processor_id.c
  cpumask: Optimize cpumask_of_cpu in kernel/time/tick-common.c
  cpumask: Optimize cpumask_of_cpu in drivers/misc/sgi-xp/xpc_main.c
  cpumask: Optimize cpumask_of_cpu in arch/x86/kernel/ldt.c
  cpumask: Optimize cpumask_of_cpu in arch/x86/kernel/io_apic_64.c
  cpumask: Replace cpumask_of_cpu with cpumask_of_cpu_ptr
  Revert "cpumask: introduce new APIs"
  cpumask: make for_each_cpu_mask a bit smaller
  net: Pass reference to cpumask variable in net/sunrpc/svc.c
  ...

Fix up trivial conflicts in drivers/cpufreq/cpufreq.c manually
2008-07-23 18:37:44 -07:00
Linus Torvalds 47c317a7aa Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: dump more data on slab corruption
  SLUB: simplify re on_each_cpu()
2008-07-21 12:40:15 -07:00
Ingo Molnar eb6a12c242 Merge branch 'linus' into cpus4096-for-linus
Conflicts:

	net/sunrpc/svc.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-21 17:19:50 +02:00
David S. Miller db7a94d60f highmem: Export totalhigh_pages.
Hash et al. sizing code in SCTP wants to make the
calculation totalram_pages - totalhigh_pages, just
like TCP.  But this requires an export for the
CONFIG_HIGHMEM case to work.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-19 22:39:46 -07:00
Pekka Enberg 0ebd652b35 slub: dump more data on slab corruption
The limit of 128 bytes is too small when debugging slab corruption of the skb
cache, for example. So increase the limit to PAGE_SIZE to make debugging
corruptions easier.

Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-07-19 14:17:22 +03:00
Ingo Molnar bb2c018b09 Merge branch 'linus' into cpus4096
Conflicts:

	drivers/acpi/processor_throttling.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 22:00:54 +02:00
Alexey Dobriyan 41ab8592ca SLUB: simplify re on_each_cpu()
on_each_cpu() expands to function call on UP, too.

Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-07-16 23:55:00 +03:00
Benjamin Herrenschmidt 84c3d4aaec Merge commit 'origin/master'
Manual merge of:

	arch/powerpc/Kconfig
	arch/powerpc/kernel/stacktrace.c
	arch/powerpc/mm/slice.c
	arch/ppc/kernel/smp.c
2008-07-16 11:07:59 +10:00
Ingo Molnar 82638844d9 Merge branch 'linus' into cpus4096
Conflicts:

	arch/x86/xen/smp.c
	kernel/sched_rt.c
	net/iucv/iucv.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16 00:29:07 +02:00
Ingo Molnar 1a781a777b Merge branch 'generic-ipi' into generic-ipi-for-linus
Conflicts:

	arch/powerpc/Kconfig
	arch/s390/kernel/time.c
	arch/x86/kernel/apic_32.c
	arch/x86/kernel/cpu/perfctr-watchdog.c
	arch/x86/kernel/i8259_64.c
	arch/x86/kernel/ldt.c
	arch/x86/kernel/nmi_64.c
	arch/x86/kernel/smpboot.c
	arch/x86/xen/smp.c
	include/asm-x86/hw_irq_32.h
	include/asm-x86/hw_irq_64.h
	include/asm-x86/mach-default/irq_vectors.h
	include/asm-x86/mach-voyager/irq_vectors.h
	include/asm-x86/smp.h
	kernel/Makefile

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15 21:55:59 +02:00
Linus Torvalds b9d2252c1e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slab: rename slab_destroy_objs
  slub: current is always valid
  slub: Add check for kfree() of non slab objects.
2008-07-15 11:26:14 -07:00
Rabin Vincent e79aec291d slab: rename slab_destroy_objs
With the removal of destructors, slab_destroy_objs no longer actually
destroys any objects, making the kernel doc incorrect and the function
name misleading.

In keeping with the other debug functions, rename it to
slab_destroy_debugcheck and drop the kernel doc.

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-07-15 20:36:02 +03:00
Alexey Dobriyan 88e4ccf294 slub: current is always valid
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-07-15 20:36:01 +03:00
Christoph Lameter 0937502af7 slub: Add check for kfree() of non slab objects.
We can detect kfree()s on non slab objects by checking for PageCompound().
Works in the same way as for ksize. This helped me catch an invalid
kfree().

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-07-15 20:36:01 +03:00
Linus Torvalds 8d2567a620 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (61 commits)
  ext4: Documention update for new ordered mode and delayed allocation
  ext4: do not set extents feature from the kernel
  ext4: Don't allow nonextenst mount option for large filesystem
  ext4: Enable delalloc by default.
  ext4: delayed allocation i_blocks fix for stat
  ext4: fix delalloc i_disksize early update issue
  ext4: Handle page without buffers in ext4_*_writepage()
  ext4: Add ordered mode support for delalloc
  ext4: Invert lock ordering of page_lock and transaction start in delalloc
  mm: Add range_cont mode for writeback
  ext4: delayed allocation ENOSPC handling
  percpu_counter: new function percpu_counter_sum_and_set
  ext4: Add delayed allocation support in data=writeback mode
  vfs: add hooks for ext4's delayed allocation support
  jbd2: Remove data=ordered mode support using jbd buffer heads
  ext4: Use new framework for data=ordered mode in JBD2
  jbd2: Implement data=ordered mode handling via inodes
  vfs: export filemap_fdatawrite_range()
  ext4: Fix lock inversion in ext4_ext_truncate()
  ext4: Invert the locking order of page_lock and transaction start
  ...
2008-07-15 08:36:38 -07:00
Benjamin Herrenschmidt 43d2548bb2 Merge commit '85082fd7cbe3173198aac0eb5e85ab1edcc6352c' into test-build
Manual fixup of:

	arch/powerpc/Kconfig
2008-07-15 15:44:51 +10:00
Linus Torvalds e18425a0ab Merge branch 'tracing/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (228 commits)
  ftrace: build fix for ftraced_suspend
  ftrace: separate out the function enabled variable
  ftrace: add ftrace_kill_atomic
  ftrace: use current CPU for function startup
  ftrace: start wakeup tracing after setting function tracer
  ftrace: check proper config for preempt type
  ftrace: trace schedule
  ftrace: define function trace nop
  ftrace: move sched_switch enable after markers
  ftrace: prevent ftrace modifications while being kprobe'd, v2
  fix "ftrace: store mcount address in rec->ip"
  mmiotrace broken in linux-next (8-bit writes only)
  ftrace: avoid modifying kprobe'd records
  ftrace: freeze kprobe'd records
  kprobes: enable clean usage of get_kprobe
  ftrace: store mcount address in rec->ip
  ftrace: build fix with gcc 4.3
  namespacecheck: fixes
  ftrace: fix "notrace" filtering priority
  ftrace: fix printout
  ...
2008-07-14 14:49:54 -07:00
Linus Torvalds a3da5bf84a Merge branch 'x86/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (821 commits)
  x86: make 64bit hpet_set_mapping to use ioremap too, v2
  x86: get x86_phys_bits early
  x86: max_low_pfn_mapped fix #4
  x86: change _node_to_cpumask_ptr to return const ptr
  x86: I/O APIC: remove an IRQ2-mask hack
  x86: fix numaq_tsc_disable calling
  x86, e820: remove end_user_pfn
  x86: max_low_pfn_mapped fix, #3
  x86: max_low_pfn_mapped fix, #2
  x86: max_low_pfn_mapped fix, #1
  x86_64: fix delayed signals
  x86: remove conflicting nx6325 and nx6125 quirks
  x86: Recover timer_ack lost in the merge of the NMI watchdog
  x86: I/O APIC: Never configure IRQ2
  x86: L-APIC: Always fully configure IRQ0
  x86: L-APIC: Set IRQ0 as edge-triggered
  x86: merge dwarf2 headers
  x86: use AS_CFI instead of UNWIND_INFO
  x86: use ignore macro instead of hash comment
  x86: use matching CFI_ENDPROC
  ...
2008-07-14 13:43:24 -07:00
Linus Torvalds 6c118e43dc Merge git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6: (31 commits)
  avr32: Fix typo of IFSR in a comment in the PIO header file
  avr32: Power Management support ("standby" and "mem" modes)
  avr32: Add system device for the internal interrupt controller (intc)
  avr32: Add simple SRAM allocator
  avr32: Enable SDRAMC clock at startup
  rtc-at32ap700x: Enable wakeup
  macb: Basic suspend/resume support
  atmel_serial: Drain console TX shifter before suspending
  atmel_serial: Fix build on avr32 with CONFIG_PM enabled
  avr32: Use a quicklist for PTE allocation as well
  avr32: Use a quicklist for PGD allocation
  avr32: Cover the kernel page tables in the user PGDs
  avr32: Store virtual addresses in the PGD
  avr32: Remove useless zeroing of swapper_pg_dir at startup
  avr32: Clean up and optimize the TLB operations
  avr32: Rename at32ap.c -> pdc.c
  avr32: Move setup_platform() into chip-specific file
  avr32: Kill special exception handler sections
  avr32: Kill unneeded #include <asm/pgalloc.h> from asm/mmu_context.h
  avr32: Clean up time.c #includes
  ...
2008-07-14 13:37:29 -07:00
Linus Torvalds b7f80afa28 Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6
* 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6: (71 commits)
  [S390] sclp_tty: Fix scheduling while atomic bug.
  [S390] sclp_tty: remove ioctl interface.
  [S390] Remove P390 support.
  [S390] Cleanup vmcp printk messages.
  [S390] Cleanup lcs printk messages.
  [S390] Cleanup kprobes printk messages.
  [S390] Cleanup vmwatch printk messages.
  [S390] Cleanup dcssblk printk messages.
  [S390] Cleanup zfcp dumper printk messages.
  [S390] Cleanup vmlogrdr printk messages.
  [S390] Cleanup s390 debug feature print messages.
  [S390] Cleanup monreader printk messages.
  [S390] Cleanup appldata printk messages.
  [S390] Cleanup smsgiucv printk messages.
  [S390] Cleanup cpacf printk messages.
  [S390] Cleanup qeth print messages.
  [S390] Cleanup netiucv printk messages.
  [S390] Cleanup iucv printk messages.
  [S390] Cleanup sclp printk messages.
  [S390] Cleanup zcrypt printk messages.
  ...
2008-07-14 13:25:01 -07:00
Linus Torvalds 7daf705f36 Start using the new '%pS' infrastructure to print symbols
This simplifies the code significantly, and was the whole point of the
exercise.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-14 12:12:53 -07:00
Ingo Molnar 5806b81ac1 Merge branch 'auto-ftrace-next' into tracing/for-linus
Conflicts:

	arch/x86/kernel/entry_32.S
	arch/x86/kernel/process_32.c
	arch/x86/kernel/process_64.c
	arch/x86/lib/Makefile
	include/asm-x86/irqflags.h
	kernel/Makefile
	kernel/sched.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-14 16:11:52 +02:00
Heiko Carstens 421c175c4d [S390] Add support for memory hot-add.
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:16 +02:00
Benjamin Herrenschmidt 11c2d8174e Merge commit 'origin/HEAD' into test-merge
Manual fixup of include/asm-powerpc/pgtable-ppc64.h
2008-07-14 14:29:49 +10:00
Ingo Molnar ae94b8075a Merge branch 'linus' into x86/core
Conflicts:

	arch/x86/mm/ioremap.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-12 07:29:02 +02:00
Aneesh Kumar K.V 06d6cf6959 mm: Add range_cont mode for writeback
Filesystems like ext4 needs to start a new transaction in
the writepages for block allocation. This happens with delayed
allocation and there is limit to how many credits we can request
from the journal layer. So we call write_cache_pages multiple
times with wbc->nr_to_write set to the maximum possible value
limitted by the max journal credits available.

Add a new mode to writeback that enables us to handle this
behaviour. In the new mode we update the wbc->range_start
to point to the new offset to be written. Next call to
call to write_cache_pages will start writeout from specified
range_start offset. In the new mode we also limit writing
to the specified wbc->range_end.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11 19:27:31 -04:00
Jan Kara f4c0a0fdfa vfs: export filemap_fdatawrite_range()
Make filemap_fdatawrite_range() function public, so that it can later
be used in ordered mode rewrite by JBD/JBD2.

Signed-off-by: Jan Kara <jack@suse.cz>
2008-07-11 19:27:31 -04:00
Dmitry Adamushko bdb2192851 slub: Fix use-after-preempt of per-CPU data structure
Vegard Nossum reported a crash in kmem_cache_alloc():

	BUG: unable to handle kernel paging request at da87d000
	IP: [<c01991c7>] kmem_cache_alloc+0xc7/0xe0
	*pde = 28180163 *pte = 1a87d160
	Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC
	Pid: 3850, comm: grep Not tainted (2.6.26-rc9-00059-gb190333 #5)
	EIP: 0060:[<c01991c7>] EFLAGS: 00210203 CPU: 0
	EIP is at kmem_cache_alloc+0xc7/0xe0
	EAX: 00000000 EBX: da87c100 ECX: 1adad71a EDX: 6b6b6b6b
	ESI: 00200282 EDI: da87d000 EBP: f60bfe74 ESP: f60bfe54
	DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068

and analyzed it:

  "The register %ecx looks innocent but is very important here. The disassembly:

       mov    %edx,%ecx
       shr    $0x2,%ecx
       rep stos %eax,%es:(%edi) <-- the fault

   So %ecx has been loaded from %edx... which is 0x6b6b6b6b/POISON_FREE.
   (0x6b6b6b6b >> 2 == 0x1adadada.)

   %ecx is the counter for the memset, from here:

       memset(object, 0, c->objsize);

  i.e. %ecx was loaded from c->objsize, so "c" must have been freed.
  Where did "c" come from? Uh-oh...

       c = get_cpu_slab(s, smp_processor_id());

  This looks like it has very much to do with CPU hotplug/unplug. Is
  there a race between SLUB/hotplug since the CPU slab is used after it
  has been freed?"

Good analysis.

Yeah, it's possible that a caller of kmem_cache_alloc() -> slab_alloc()
can be migrated on another CPU right after local_irq_restore() and
before memset().  The inital cpu can become offline in the mean time (or
a migration is a consequence of the CPU going offline) so its
'kmem_cache_cpu' structure gets freed ( slab_cpuup_callback).

At some point of time the caller continues on another CPU having an
obsolete pointer...

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-10 15:18:50 -07:00
Ingo Molnar bac0c9103b Merge branch 'tracing/ftrace' into auto-ftrace-next 2008-07-10 11:43:00 +02:00
Dave Kleikamp b845f313d7 mm: Allow architectures to define additional protection bits
This patch allows architectures to define functions to deal with
additional protections bits for mmap() and mprotect().

arch_calc_vm_prot_bits() maps additonal protection bits to vm_flags
arch_vm_get_page_prot() maps additional vm_flags to the vma's vm_page_prot
arch_validate_prot() checks for valid values of the protection bits

Note: vm_get_page_prot() is now pretty ugly, but the generated code
should be identical for architectures that don't define additional
protection bits.

Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-09 16:30:45 +10:00
Paul Jackson 5dab8ec139 mm, generic, x86 boot: more tweaks to hex prints of some pfn addresses
Fix some problems with (and applies on top of) a previous patch:
  x86 boot: show pfn addresses in hex not decimal in some kernel info printks

Primarily change "0x%8lx" format, which displays with a right aligned
space filled hex number (spaces between the "0x" prefix and the number),
into "%0#10lx" format, which zero fills instead of space fills, and
which uses the printf flag '#' to request the "0x" prefix instead of
hard coding it.

Also replace some other "0x%lx" formats with "%#lx", making use of the
'#' printf flag again.

Signed-off-by: Paul Jackson <pj@sgi.com>
Cc: "Yinghai Lu" <yhlu.kernel@gmail.com>
Cc: "Jack Steiner" <steiner@sgi.com>
Cc: "Mike Travis" <travis@sgi.com>
Cc: "Huang
Cc: Ying" <ying.huang@intel.com>
Cc: "Andi Kleen" <andi@firstfloor.org>
Cc: "Andrew Morton" <akpm@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08 13:10:40 +02:00
Paul Jackson 2bc0d2615a x86 boot: more consistently use type int for node ids
Everywhere I look, node id's are of type 'int', except in this one
case, which has 'unsigned long'.  Change this one to 'int' as well.
There is nothing special about the way this variable 'nid' is used in
this routine to justify using an unusual type here.

Signed-off-by: Paul Jackson <pj@sgi.com>
Cc: "Yinghai Lu" <yhlu.kernel@gmail.com>
Cc: "Jack Steiner" <steiner@sgi.com>
Cc: "Mike Travis" <travis@sgi.com>
Cc: "Huang
Cc: Ying" <ying.huang@intel.com>
Cc: "Andi Kleen" <andi@firstfloor.org>
Cc: "Andrew Morton" <akpm@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08 12:51:38 +02:00
Paul Jackson e2fc252e0c x86 boot: show pfn addresses in hex not decimal in some kernel info printks
Page frame numbers (the portion of physical addresses above the low
order page offsets) are displayed in several kernel debug and info
prints in decimal, not hex.  Decimal addresse are unreadable.  Use hex.

Signed-off-by: Paul Jackson <pj@sgi.com>
Cc: "Yinghai Lu" <yhlu.kernel@gmail.com>
Cc: "Jack Steiner" <steiner@sgi.com>
Cc: "Mike Travis" <travis@sgi.com>
Cc: "Huang
Cc: Ying" <ying.huang@intel.com>
Cc: "Andi Kleen" <andi@firstfloor.org>
Cc: "Andrew Morton" <akpm@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08 12:51:37 +02:00
Yinghai Lu d52d53b8a5 RFC x86: try to remove arch_get_ram_range
want to remove arch_get_ram_range, and use early_node_map instead.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08 12:48:27 +02:00
Ingo Molnar 3de352bbd8 Merge branch 'x86/mpparse' into x86/devel
Conflicts:

	arch/x86/Kconfig
	arch/x86/kernel/io_apic_32.c
	arch/x86/kernel/setup_64.c
	arch/x86/mm/init_32.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08 11:14:58 +02:00
Yinghai Lu b5bc6c0e55 x86, mm: use add_highpages_with_active_regions() for high pages init v2
use early_node_map to init high pages, so we can remove page_is_ram() and
page_is_reserved_early() in the big loop with add_one_highpage

also remove page_is_reserved_early(), it is not needed anymore.

v2: fix the build of other platforms

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08 10:37:25 +02:00
Yinghai Lu cc1050bafe x86: replace shrink_active_range() with remove_active_range()
in case we have kva before ramdisk on a node, we still need to use
those ranges.

v2: reserve_early kva ram area, in case there are holes in highmem, to avoid
    those area could be treat as free high pages.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08 10:36:29 +02:00
Ingo Molnar 896395c290 Merge branch 'linus' into tmp.x86.mpparse.new 2008-07-08 10:32:56 +02:00
Ingo Molnar 6924d1ab8b Merge branches 'x86/numa-fixes', 'x86/apic', 'x86/apm', 'x86/bitops', 'x86/build', 'x86/cleanups', 'x86/cpa', 'x86/cpu', 'x86/defconfig', 'x86/gart', 'x86/i8259', 'x86/intel', 'x86/irqstats', 'x86/kconfig', 'x86/ldt', 'x86/mce', 'x86/memtest', 'x86/pat', 'x86/ptemask', 'x86/resumetrace', 'x86/threadinfo', 'x86/timers', 'x86/vdso' and 'x86/xen' into x86/devel 2008-07-08 09:16:56 +02:00
Ingo Molnar 68083e05d7 Merge commit 'v2.6.26-rc9' into cpus4096 2008-07-06 14:23:39 +02:00
David Rientjes d79df630f6 mempolicy: mask off internal flags for userspace API
Flags considered internal to the mempolicy kernel code are stored as part
of the "flags" member of struct mempolicy.

Before exposing a policy type to userspace via get_mempolicy(), these
internal flags must be masked.  Flags exposed to userspace, however,
should still be returned to the user.

Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04 13:03:05 -07:00
Oleg Nesterov 7a36a752d0 get_user_pages(): fix possible page leak on oom
get_user_pages() must not return the error when i != 0.  When pages !=
NULL we have i get_page()'ed pages.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04 10:40:04 -07:00
Peter Zijlstra 251b97f552 mm: dirty page accounting vs VM_MIXEDMAP
Dirty page accounting accurately measures the amound of dirty pages in
writable shared mappings by mapping the pages RO (as indicated by
vma_wants_writenotify).  We then trap on first write and call
set_page_dirty() on the page, after which we map the page RW and
continue execution.

When we launder dirty pages, we call clear_page_dirty_for_io() which
clears both the dirty flag, and maps the page RO again before we start
writeout so that the story can repeat itself.

vma_wants_writenotify() excludes VM_PFNMAP on the basis that we cannot
do the regular dirty page stuff on raw PFNs and the memory isn't going
anywhere anyway.

The recently introduced VM_MIXEDMAP mixes both !pfn_valid() and
pfn_valid() pages in a single mapping.

We can't do dirty page accounting on !pfn_valid() pages as stated
above, and mapping them RO causes them to be COW'ed on write, which
breaks VM_SHARED semantics.

Excluding VM_MIXEDMAP in vma_wants_writenotify() would mean we don't do
the regular dirty page accounting for the pfn_valid() pages, which
would bring back all the head-aches from inaccurate dirty page
accounting.

So instead, we let the !pfn_valid() pages get mapped RO, but fix them
up unconditionally in the fault path.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Acked-by: Hugh Dickins <hugh@veritas.com>
Cc: "Jared Hulbert" <jaredeh@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04 10:40:04 -07:00
Christoph Lameter cde5353599 Christoph has moved
Remove all clameter@sgi.com addresses from the kernel tree since they will
become invalid on June 27th.  Change my maintainer email address for the
slab allocators to cl@linux-foundation.org (which will be the new email
address for the future).

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04 10:40:04 -07:00
Linus Torvalds 3ea9eed493 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: Do not use 192 byte sized cache if minimum alignment is 128 byte
2008-07-04 09:48:21 -07:00
Mel Gorman 494de90098 Do not overwrite nr_zones on !NUMA when initialising zlcache_ptr
The non-NUMA case of build_zonelist_cache() would initialize the
zlcache_ptr for both node_zonelists[] to NULL.

Which is problematic, since non-NUMA only has a single node_zonelists[]
entry, and trying to zero the non-existent second one just overwrote the
nr_zones field instead.

As kswapd uses this value to determine what reclaim work is necessary,
the result is that kswapd never reclaims.  This causes processes to
stall frequently in low-memory situations as they always direct reclaim.
This patch initialises zlcache_ptr correctly.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Tested-by: Dan Williams <dan.j.williams@intel.com>
[ Simplified patch a bit ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-03 09:22:59 -07:00
Christoph Lameter 41d54d3bf8 slub: Do not use 192 byte sized cache if minimum alignment is 128 byte
The 192 byte cache is not necessary if we have a basic alignment of 128
byte. If it would be used then the 192 would be aligned to the next 128 byte
boundary which would result in another 256 byte cache. Two 256 kmalloc caches
cause sysfs to complain about a duplicate entry.

MIPS needs 128 byte aligned kmalloc caches and spits out warnings on boot without
this patch.

Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-07-03 19:01:55 +03:00
Haavard Skinnemoen 38510754a5 avr32: Use a quicklist for PTE allocation as well
Using a quicklist to allocate PTEs might be slightly faster than using
the page allocator directly since we might avoid zeroing the page
after each allocation.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-07-02 11:01:29 +02:00
Jens Axboe 15c8b6c1aa on_each_cpu(): kill unused 'retry' parameter
It's not even passed on to smp_call_function() anymore, since that
was removed. So kill it.

Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-06-26 11:24:38 +02:00
Jeremy Fitzhardinge 1ea0704e0d mm: add a ptep_modify_prot transaction abstraction
This patch adds an API for doing read-modify-write updates to a pte's
protection bits which may race against hardware updates to the pte.
After reading the pte, the hardware may asynchonously set the accessed
or dirty bits on a pte, which would be lost when writing back the
modified pte value.

The existing technique to handle this race is to use
ptep_get_and_clear() atomically fetch the old pte value and clear it
in memory.  This has the effect of marking the pte as non-present,
which will prevent the hardware from updating its state.  When the new
value is written back, the pte will be present again, and the hardware
can resume updating the access/dirty flags.

When running in a virtualized environment, pagetable updates are
relatively expensive, since they generally involve some trap into the
hypervisor.  To mitigate the cost of these updates, we tend to batch
them.

However, because of the atomic nature of ptep_get_and_clear(), it is
inherently non-batchable.  This new interface allows batching by
giving the underlying implementation enough information to open a
transaction between the read and write phases:

ptep_modify_prot_start() returns the current pte value, and puts the
  pte entry into a state where either the hardware will not update the
  pte, or if it does, the updates will be preserved on commit.

ptep_modify_prot_commit() writes back the updated pte, makes sure that
  any hardware updates made since ptep_modify_prot_start() are
  preserved.

ptep_modify_prot_start() and _commit() must be exactly paired, and
used while holding the appropriate pte lock.  They do not protect
against other software updates of the pte in any way.

The current implementations of ptep_modify_prot_start and _commit are
functionally unchanged from before: _start() uses ptep_get_and_clear()
fetch the pte and zero the entry, preventing any hardware updates.
_commit() simply writes the new pte value back knowing that the
hardware has not updated the pte in the meantime.

The only current user of this interface is mprotect

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-25 15:15:53 +02:00
Ingo Molnar 97e6722b8d Merge branch 'linus' into tracing/ftrace 2008-06-25 12:27:56 +02:00
Nick Piggin 945754a175 mm: fix race in COW logic
There is a race in the COW logic.  It contains a shortcut to avoid the
COW and reuse the page if we have the sole reference on the page,
however it is possible to have two racing do_wp_page()ers with one
causing the other to mistakenly believe it is safe to take the shortcut
when it is not.  This could lead to data corruption.

Process 1 and process2 each have a wp pte of the same anon page (ie.
one forked the other).  The page's mapcount is 2.  Then they both
attempt to write to it around the same time...

  proc1				proc2 thr1			proc2 thr2
  CPU0				CPU1				CPU3
  do_wp_page()			do_wp_page()
				 trylock_page()
				  can_share_swap_page()
				   load page mapcount (==2)
				  reuse = 0
				 pte unlock
				 copy page to new_page
				 pte lock
				 page_remove_rmap(page);
   trylock_page()
    can_share_swap_page()
     load page mapcount (==1)
    reuse = 1
   ptep_set_access_flags (allow W)

  write private key into page
								read from page
				ptep_clear_flush()
				set_pte_at(pte of new_page)

Fix this by moving the page_remove_rmap of the old page after the pte
clear and flush.  Potentially the entire branch could be moved down
here, but in order to stay consistent, I won't (should probably move all
the *_mm_counter stuff with one patch).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Hugh Dickins <hugh@veritas.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-23 11:28:32 -07:00
Linus Torvalds 672ca28e30 Fix ZERO_PAGE breakage with vmware
Commit 89f5b7da2a ("Reinstate ZERO_PAGE
optimization in 'get_user_pages()' and fix XIP") broke vmware, as
reported by Jeff Chua:

  "This broke vmware 6.0.4.
   Jun 22 14:53:03.845: vmx| NOT_IMPLEMENTED
   /build/mts/release/bora-93057/bora/vmx/main/vmmonPosix.c:774"

and the reason seems to be that there's an old bug in how we handle do
FOLL_ANON on VM_SHARED areas in get_user_pages(), but since it only
triggered if the whole page table was missing, nobody had apparently hit
it before.

The recent changes to 'follow_page()' made the FOLL_ANON logic trigger
not just for whole missing page tables, but for individual pages as
well, and exposed this problem.

This fixes it by making the test for when FOLL_ANON is used more
careful, and also makes the code easier to read and understand by moving
the logic to a separate inline function.

Reported-and-tested-by: Jeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-23 11:21:37 -07:00
Ingo Molnar f34bfb1bee Merge branch 'linus' into tracing/ftrace 2008-06-23 11:11:42 +02:00
Christoph Lameter 481c5346d0 Slab: Fix memory leak in fallback_alloc()
The zonelist patches caused the loop that checks for available
objects in permitted zones to not terminate immediately. One object
per zone per allocation may be allocated and then abandoned.

Break the loop when we have successfully allocated one object.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-21 16:51:02 -07:00
Bernhard Walle 71c2742f5e Add return value to reserve_bootmem_node()
This patch changes the function reserve_bootmem_node() from void to int,
returning -ENOMEM if the allocation fails.

This fixes a build problem on x86 with CONFIG_KEXEC=y and
CONFIG_NEED_MULTIPLE_NODES=y

Signed-off-by: Bernhard Walle <bwalle@suse.de>
Reported-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-21 11:25:10 -07:00
Linus Torvalds 89f5b7da2a Reinstate ZERO_PAGE optimization in 'get_user_pages()' and fix XIP
KAMEZAWA Hiroyuki and Oleg Nesterov point out that since the commit
557ed1fa26 ("remove ZERO_PAGE") removed
the ZERO_PAGE from the VM mappings, any users of get_user_pages() will
generally now populate the VM with real empty pages needlessly.

We used to get the ZERO_PAGE when we did the "handle_mm_fault()", but
since fault handling no longer uses ZERO_PAGE for new anonymous pages,
we now need to handle that special case in follow_page() instead.

In particular, the removal of ZERO_PAGE effectively removed the core
file writing optimization where we would skip writing pages that had not
been populated at all, and increased memory pressure a lot by allocating
all those useless newly zeroed pages.

This reinstates the optimization by making the unmapped PTE case the
same as for a non-existent page table, which already did this correctly.

While at it, this also fixes the XIP case for follow_page(), where the
caller could not differentiate between the case of a page that simply
could not be used (because it had no "struct page" associated with it)
and a page that just wasn't mapped.

We do that by simply returning an error pointer for pages that could not
be turned into a "struct page *".  The error is arbitrarily picked to be
EFAULT, since that was what get_user_pages() already used for the
equivalent IO-mapped page case.

[ Also removed an impossible test for pte_offset_map_lock() failing:
  that's not how that function works ]

Acked-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Nick Piggin <npiggin@suse.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-20 11:18:25 -07:00
Ingo Molnar e765ee90da Merge branch 'linus' into tracing/ftrace 2008-06-16 11:15:58 +02:00
Dave Hansen 2165009bdf pagemap: pass mm into pagewalkers
We need this at least for huge page detection for now, because powerpc
needs the vm_area_struct to be able to determine whether a virtual address
is referring to a huge page (its pmd_huge() doesn't work).

It might also come in handy for some of the other users.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-12 18:05:41 -07:00
kosaki.motohiro@jp.fujitsu.com c700be3d13 mm: fix incorrect variable type in do_try_to_free_pages()
"Smarter retry of costly-order allocations" patch series change behaver of
do_try_to_free_pages().  But unfortunately ret variable type was
unchanged.

Thus an overflow is possible.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-12 18:05:39 -07:00
Paul Mundt 5a1603be58 nommu: Correct kobjsize() page validity checks.
This implements a few changes on top of the recent kobjsize() refactoring
introduced by commit 6cfd53fc03.

As Christoph points out:

	virt_to_head_page cannot return NULL. virt_to_page also
	does not return NULL. pfn_valid() needs to be used to
	figure out if a page is valid.  Otherwise the page struct
	reference that was returned may have PageReserved() set
	to indicate that it is not a valid page.

As discussed further in the thread, virt_addr_valid() is the preferable
way to validate the object pointer in this case. In addition to fixing
up the reserved page case, it also has the benefit of encapsulating the
hack introduced by commit 4016a1390d on
the impacted platforms, allowing us to get rid of the extra checking in
kobjsize() for the platforms that don't perform this type of bizarre
memory_end abuse (every nommu platform that isn't blackfin). If blackfin
decides to get in line with every other platform and use PageReserved
for the DMA pages in question, kobjsize() will also continue to work
fine.

It also turns out that compound_order() will give us back 0-order for
non-head pages, so we can get rid of the PageCompound check and just
use compound_order() directly. Clean that up while we're at it.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-12 07:56:17 -07:00
Yinghai Lu cc1a9d86ce mm, x86: shrink_active_range() should check all
Now we are using register_e820_active_regions() instead of
add_active_range() directly. So end_pfn could be different between the
value in early_node_map to node_end_pfn.

So we need to make shrink_active_range() smarter.

shrink_active_range() is a generic MM function in mm/page_alloc.c but
it is only used on 32-bit x86. Should we move it back to some file in
arch/x86?

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-10 11:31:44 +02:00
Russ Anderson dfa7e20cc0 mm: Minor clean-up of page flags in mm/page_alloc.c
Minor source code cleanup of page flags in mm/page_alloc.c.
Move the definition of the groups of bits to page-flags.h.

The purpose of this clean up is that the next patch will
conditionally add a page flag to the groups.  Doing that
in a header file is cleaner than adding #ifdefs to the
C code.

Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-09 10:22:24 -07:00
Paul Mundt 6cfd53fc03 nommu: fix kobjsize() for SLOB and SLUB
kobjsize() has been abusing page->index as a method for sorting out
compound order, which blows up both for page cache pages, and SLOB's
reuse of the index in struct slob_page.

Presently we are not able to accurately size arbitrary pointers that
don't come from kmalloc(), so the best we can do is sort out the
compound order from the head page if it's a compound page, or default
to 0-order if it's impossible to ksize() the object.

Obviously this leaves quite a bit to be desired in terms of object
sizing accuracy, but the behaviour is unchanged over the existing
implementation, while fixing the page->index oopses originally reported
here:

	http://marc.info/?l=linux-mm&m=121127773325245&w=2

Accuracy could also be improved by having SLUB and SLOB both set PG_slab
on ksizeable pages, rather than just handling the __GFP_COMP cases
irregardless of the PG_slab setting, as made possibly with Pekka's
patches:

	http://marc.info/?l=linux-kernel&m=121139439900534&w=2
	http://marc.info/?l=linux-kernel&m=121139440000537&w=2
	http://marc.info/?l=linux-kernel&m=121139440000540&w=2

This is primarily a bugfix for nommu systems for 2.6.26, with the aim
being to gradually kill off kobjsize() and its particular brand of
object abuse entirely.

Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06 11:29:09 -07:00
Jiri Kosina a5b4592cf7 brk: make sys_brk() honor COMPAT_BRK when computing lower bound
Fix a regression introduced by

commit 4cc6028d40
Author: Jiri Kosina <jkosina@suse.cz>
Date:   Wed Feb 6 22:39:44 2008 +0100

    brk: check the lower bound properly

The check in sys_brk() on minimum value the brk might have must take
CONFIG_COMPAT_BRK setting into account.  When this option is turned on
(i.e.  we support ancient legacy binaries, e.g.  libc5-linked stuff), the
lower bound on brk value is mm->end_code, otherwise the brk start is
allowed to be arbitrarily shifted.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06 11:29:09 -07:00
Nick Piggin 4647875819 hugetlb: fix lockdep error
=============================================
[ INFO: possible recursive locking detected ]
2.6.26-rc4 #30
---------------------------------------------
heap-overflow/2250 is trying to acquire lock:
 (&mm->page_table_lock){--..}, at: [<c0000000000cf2e8>] .copy_hugetlb_page_range+0x108/0x280

but task is already holding lock:
 (&mm->page_table_lock){--..}, at: [<c0000000000cf2dc>] .copy_hugetlb_page_range+0xfc/0x280

other info that might help us debug this:
3 locks held by heap-overflow/2250:
 #0:  (&mm->mmap_sem){----}, at: [<c000000000050e44>] .dup_mm+0x134/0x410
 #1:  (&mm->mmap_sem/1){--..}, at: [<c000000000050e54>] .dup_mm+0x144/0x410
 #2:  (&mm->page_table_lock){--..}, at: [<c0000000000cf2dc>] .copy_hugetlb_page_range+0xfc/0x280

stack backtrace:
Call Trace:
[c00000003b2774e0] [c000000000010ce4] .show_stack+0x74/0x1f0 (unreliable)
[c00000003b2775a0] [c0000000003f10e0] .dump_stack+0x20/0x34
[c00000003b277620] [c0000000000889bc] .__lock_acquire+0xaac/0x1080
[c00000003b277740] [c000000000089000] .lock_acquire+0x70/0xb0
[c00000003b2777d0] [c0000000003ee15c] ._spin_lock+0x4c/0x80
[c00000003b277870] [c0000000000cf2e8] .copy_hugetlb_page_range+0x108/0x280
[c00000003b277950] [c0000000000bcaa8] .copy_page_range+0x558/0x790
[c00000003b277ac0] [c000000000050fe0] .dup_mm+0x2d0/0x410
[c00000003b277ba0] [c000000000051d24] .copy_process+0xb94/0x1020
[c00000003b277ca0] [c000000000052244] .do_fork+0x94/0x310
[c00000003b277db0] [c000000000011240] .sys_clone+0x60/0x80
[c00000003b277e30] [c0000000000078c4] .ppc_clone+0x8/0xc

Fix is the same way that mm/memory.c copy_page_range does the
lockdep annotation.

Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06 11:29:09 -07:00
Yinghai Lu e8c27ac919 x86, numa, 32-bit: print out debug info on all kvas
also fix the print out of node_remap_end_vaddr

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-03 13:26:26 +02:00
Linus Torvalds 1434b65731 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: ksize() abuse checks
  slob: Fix to return wrong pointer
2008-05-26 10:21:26 -07:00
Heiko Carstens cd94b9dbfa memory hotplug: fix early allocation handling
Trying to add memory via add_memory() from within an initcall function
results in

bootmem alloc of 163840 bytes failed!
Kernel panic - not syncing: Out of memory

This is caused by zone_wait_table_init() which uses system_state to decide
if it should use the bootmem allocator or not.

When initcalls are handled the system_state is still SYSTEM_BOOTING but
the bootmem allocator doesn't work anymore.  So the allocation will fail.

To fix this use slab_is_available() instead as indicator like we do it
everywhere else.

[akpm@linux-foundation.org: coding-style fix]
Reviewed-by: Andy Whitcroft <apw@shadowen.org>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-24 09:56:12 -07:00
Andy Whitcroft 7eb54824b7 zonelists: handle a node zonelist with no applicable entries
When booting 2.6.26-rc3 on a multi-node x86_32 numa system we are seeing
panics when trying node local allocations:

 BUG: unable to handle kernel NULL pointer dereference at 0000034c
 IP: [<c1042507>] get_page_from_freelist+0x4a/0x18e
 *pdpt = 00000000013a7001 *pde = 0000000000000000
 Oops: 0000 [#1] SMP
 Modules linked in:

 Pid: 0, comm: swapper Not tainted (2.6.26-rc3-00003-g5abc28d #82)
 EIP: 0060:[<c1042507>] EFLAGS: 00010282 CPU: 0
 EIP is at get_page_from_freelist+0x4a/0x18e
 EAX: c1371ed8 EBX: 00000000 ECX: 00000000 EDX: 00000000
 ESI: f7801180 EDI: 00000000 EBP: 00000000 ESP: c1371ec0
  DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
 Process swapper (pid: 0, ti=c1370000 task=c12f5b40 task.ti=c1370000)
 Stack: 00000000 00000000 00000000 00000000 000612d0 000412d0 00000000 000412d0
        f7801180 f7c0101c f7c01018 c10426e4 f7c01018 00000001 00000044 00000000
        00000001 c12f5b40 00000001 00000010 00000000 000412d0 00000286 000412d0
 Call Trace:
  [<c10426e4>] __alloc_pages_internal+0x99/0x378
  [<c10429ca>] __alloc_pages+0x7/0x9
  [<c105e0e8>] kmem_getpages+0x66/0xef
  [<c105ec55>] cache_grow+0x8f/0x123
  [<c105f117>] ____cache_alloc_node+0xb9/0xe4
  [<c105f427>] kmem_cache_alloc_node+0x92/0xd2
  [<c122118c>] setup_cpu_cache+0xaf/0x177
  [<c105e6ca>] kmem_cache_create+0x2c8/0x353
  [<c13853af>] kmem_cache_init+0x1ce/0x3ad
  [<c13755c5>] start_kernel+0x178/0x1ee

This occurs when we are scanning the zonelists looking for a ZONE_NORMAL
page.  In this system there is only ZONE_DMA and ZONE_NORMAL memory on
node 0, all other nodes are mapped above 4GB physical.  Here is a dump
of the zonelists from this system:

    zonelists pgdat=c1400000
     0: c14006c0:2 f7c006c0:2 f7e006c0:2 c1400360:1 c1400000:0
     1: c14006c0:2 c1400360:1 c1400000:0
    zonelists pgdat=f7c00000
     0: f7c006c0:2 f7e006c0:2 c14006c0:2 c1400360:1 c1400000:0
     1: f7c006c0:2
    zonelists pgdat=f7e00000
     0: f7e006c0:2 c14006c0:2 f7c006c0:2 c1400360:1 c1400000:0
     1: f7e006c0:2

When performing a node local allocation we call get_page_from_freelist()
looking for a page.  It in turn calls first_zones_zonelist() which returns
a preferred_zone.  Where there are no applicable zones this will be NULL.
However we use this unconditionally, leading to this panic.

Where there are no applicable zones there is no possibility of a successful
allocation, so simply fail the allocation.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-24 09:56:11 -07:00
Alan Cox 80119ef5c8 mm: fix atomic_t overflow in vm
The atomic_t type is 32bit but a 64bit system can have more than 2^32
pages of virtual address space available.  Without this we overflow on
ludicrously large mappings

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-24 09:56:09 -07:00
Johannes Weiner f723215419 mm: don't drop a partial page in a zone's memory map size
In a zone's present pages number, account for all pages occupied by the
memory map, including a partial.

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-24 09:56:07 -07:00
Nick Piggin 42172d751b mm: allow pfnmap ->fault()s
Take out an assertion to allow ->fault handlers to service PFNMAP regions.
This is required to reimplement .nopfn handlers with .fault handlers and
subsequently remove nopfn.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Jes Sorensen <jes@sgi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-24 09:56:07 -07:00
Steven Rostedt 3eefae994d ftrace: limit trace entries
Currently there is no protection from the root user to use up all of
memory for trace buffers. If the root user allocates too many entries,
the OOM killer might start kill off all tasks.

This patch adds an algorith to check the following condition:

 pages_requested > (freeable_memory + current_trace_buffer_pages) / 4

If the above is met then the allocation fails. The above prevents more
than 1/4th of freeable memory from being used by trace buffers.

To determine the freeable_memory, I made determine_dirtyable_memory in
mm/page-writeback.c global.

Special thanks goes to Peter Zijlstra for suggesting the above calculation.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 22:05:14 +02:00
Mike Travis 6d6a436087 mm: use performance variant for_each_cpu_mask_nr
Change references from for_each_cpu_mask to for_each_cpu_mask_nr
where appropriate

Reviewed-by: Paul Jackson <pj@sgi.com>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 18:35:12 +02:00
Pekka Enberg 76994412f8 slub: ksize() abuse checks
Add a WARN_ON for pages that don't have PageSlab nor PageCompound set to catch
the worst abusers of ksize() in the kernel.

Acked-by: Christoph Lameter <clameter@sgi.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-05-22 19:52:18 +03:00
Greg Kroah-Hartman 19051c5035 mm: bdi: fix race in bdi_class device creation
There is a race from when a device is created with device_create() and
then the drvdata is set with a call to dev_set_drvdata() in which a
sysfs file could be open, yet the drvdata will be NULL, causing all
sorts of bad things to happen.

This patch fixes the problem by using the new function,
device_create_vargs().

Many thanks to Arthur Jones <ajones@riverbed.com> for reporting the bug,
and testing patches out.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Arthur Jones <ajones@riverbed.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-05-20 13:31:53 -07:00
MinChan Kim 239f49c080 slob: Fix to return wrong pointer
Although slob_alloc return NULL, __kmalloc_node returns NULL + align.
Because align always can be changed, it is very hard for debugging
problem of no page if it don't return NULL.

We have to return NULL in case of no page.

[penberg@cs.helsinki.fi: fix formatting as suggested by Matt.]
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: MinChan Kim <minchan.kim@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-05-19 20:55:25 +03:00
Heiko Carstens 76cdd58e55 memory_hotplug: always initialize pageblock bitmap
Trying to online a new memory section that was added via memory hotplug
sometimes results in crashes when the new pages are added via __free_page.
 Reason for that is that the pageblock bitmap isn't initialized and hence
contains random stuff.  That means that get_pageblock_migratetype()
returns also random stuff and therefore

	list_add(&page->lru,
		&zone->free_area[order].free_list[migratetype]);

in __free_one_page() tries to do a list_add to something that isn't even
necessarily a list.

This happens since 86051ca5ea ("mm: fix
usemap initialization") which makes sure that the pageblock bitmap gets
only initialized for pages present in a zone.  Unfortunately for hot-added
memory the zones "grow" after the memmap and the pageblock memmap have
been initialized.  Which means that the new pages have an unitialized
bitmap.  To solve this the calls to grow_zone_span() and grow_pgdat_span()
are moved to __add_zone() just before the initialization happens.

The patch also moves the two functions since __add_zone() is the only
caller and I didn't want to add a forward declaration.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-14 19:11:15 -07:00
Venki Pallipadi 1c12c4cf94 mprotect: prevent alteration of the PAT bits
There is a defect in mprotect, which lets the user change the page cache
type bits by-passing the kernel reserve_memtype and free_memtype
wrappers.  Fix the problem by not letting mprotect change the PAT bits.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-14 19:11:15 -07:00
Geoff Levand fd8a4221ad memory_hotplug: check for walk_memory_resource() failure in online_pages()
Add a check to online_pages() to test for failure of
walk_memory_resource().  This fixes a condition where a failure
of walk_memory_resource() can lead to online_pages() returning
success without the requested pages being onlined.

Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Keith Mannthey <kmannth@us.ibm.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-14 19:11:14 -07:00
Heiko Carstens c3723ca387 memory hotplug: memmap_init_zone called twice
__add_zone calls memmap_init_zone twice if memory gets attached to an empty
zone.  Once via init_currently_empty_zone and once explictly right after that
call.

Looks like this is currently not a bug, however the call is superfluous and
might lead to subtle bugs if memmap_init_zone gets changed.  So make sure it
is called only once.

Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-14 19:11:14 -07:00
Miklos Szeredi 3ef0f720e4 mm: fix infinite loop in filemap_fault
filemap_fault will go into an infinite loop if ->readpage() fails
asynchronously.

AFAICS the bug was introduced by this commit, which removed the wait after the
final readpage:

   commit d00806b183
   Author: Nick Piggin <npiggin@suse.de>
   Date:   Thu Jul 19 01:46:57 2007 -0700

       mm: fix fault vs invalidate race for linear mappings

Fix by reintroducing the wait_on_page_locked() after ->readpage() to make sure
the page is up-to-date before jumping back to the beginning of the function.

I've noticed this while testing nfs exporting on fuse.  The patch
fixes it.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-14 19:11:13 -07:00
Nick Piggin 362a61ad61 fix SMP data race in pagetable setup vs walking
There is a possible data race in the page table walking code. After the split
ptlock patches, it actually seems to have been introduced to the core code, but
even before that I think it would have impacted some architectures (powerpc
and sparc64, at least, walk the page tables without taking locks eg. see
find_linux_pte()).

The race is as follows:
The pte page is allocated, zeroed, and its struct page gets its spinlock
initialized. The mm-wide ptl is then taken, and then the pte page is inserted
into the pagetables.

At this point, the spinlock is not guaranteed to have ordered the previous
stores to initialize the pte page with the subsequent store to put it in the
page tables. So another Linux page table walker might be walking down (without
any locks, because we have split-leaf-ptls), and find that new pte we've
inserted. It might try to take the spinlock before the store from the other
CPU initializes it. And subsequently it might read a pte_t out before stores
from the other CPU have cleared the memory.

There are also similar races in higher levels of the page tables. They
obviously don't involve the spinlock, but could see uninitialized memory.

Arch code and hardware pagetable walkers that walk the pagetables without
locks could see similar uninitialized memory problems, regardless of whether
split ptes are enabled or not.

I prefer to put the barriers in core code, because that's where the higher
level logic happens, but the page table accessors are per-arch, and open-coding
them everywhere I don't think is an option. I'll put the read-side barriers
in alpha arch code for now (other architectures perform data-dependent loads
in order).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-14 10:05:18 -07:00
Denis Cheng 5aecd55987 mm/pdflush.c: merge the same code in two path
Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13 08:02:24 -07:00
KOSAKI Motohiro b5be11329f make vmstat cpu-unplug safe
When accessing cpu_online_map, we should prevent dynamic changing
of cpu_online_map by get_online_cpus().

Unfortunately, all_vm_events() doesn't do that.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13 08:02:23 -07:00
Linus Torvalds 7a34912d90 Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  Revert "relay: fix splice problem"
  docbook: fix bio missing parameter
  block: use unitialized_var() in bio_alloc_bioset()
  block: avoid duplicate calls to get_part() in disk stat code
  cfq-iosched: make io priorities inherit CPU scheduling class as well as nice
  block: optimize generic_unplug_device()
  block: get rid of likely/unlikely predictions in merge logic
  vfs: splice remove_suid() cleanup
  cfq-iosched: fix RCU race in the cfq io_context destructor handling
  block: adjust tagging function queue bit locking
  block: sysfs store function needs to grab queue_lock and use queue_flag_*()
2008-05-08 10:48:36 -07:00
Benjamin Herrenschmidt 4ea33e2dc2 slub: fix atomic usage in any_slab_objects()
any_slab_objects() does an atomic_read on an atomic_long_t, this
fixes it to use atomic_long_read instead.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-08 10:46:56 -07:00
Miklos Szeredi 7f3d4ee108 vfs: splice remove_suid() cleanup
generic_file_splice_write() duplicates remove_suid() just because it
doesn't hold i_mutex.  But it grabs i_mutex inside splice_from_pipe()
anyway, so this is rather pointless.

Move locking to generic_file_splice_write() and call remove_suid() and
__splice_from_pipe() instead.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-05-07 09:29:00 +02:00
Hugh Dickins aeed5fce37 x86: fix PAE pmd_bad bootup warning
Fix warning from pmd_bad() at bootup on a HIGHMEM64G HIGHPTE x86_32.

That came from 9fc34113f6 x86: debug pmd_bad();
but we understand now that the typecasting was wrong for PAE in the previous
version: pagetable pages above 4GB looked bad and stopped Arjan from booting.

And revert that cded932b75 x86: fix pmd_bad
and pud_bad to support huge pages.  It was the wrong way round: we shouldn't
weaken every pmd_bad and pud_bad check to let huge pages slip through - in
part they check that we _don't_ have a huge page where it's not expected.

Put the x86 pmd_bad() and pud_bad() definitions back to what they have long
been: they can be improved (x86_32 should use PTE_MASK, to stop PAE thinking
junk in the upper word is good; and x86_64 should follow x86_32's stricter
comparison, to stop thinking any subset of required bits is good); but that
should be a later patch.

Fix Hans' good observation that follow_page() will never find pmd_huge()
because that would have already failed the pmd_bad test: test pmd_huge in
between the pmd_none and pmd_bad tests.  Tighten x86's pmd_huge() check?
No, once it's a hugepage entry, it can get quite far from a good pmd: for
example, PROT_NONE leaves it with only ACCESSED of the KERN_PGTABLE bits.

However... though follow_page() contains this and another test for huge
pages, so it's nice to keep it working on them, where does it actually get
called on a huge page?  get_user_pages() checks is_vm_hugetlb_page(vma) to
to call alternative hugetlb processing, as does unmap_vmas() and others.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Earlier-version-tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jeff Chua <jeff.chua.linux@gmail.com>
Cc: Hans Rosenfeld <hans.rosenfeld@amd.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-06 13:08:58 -07:00
Christoph Lameter f6acb63508 slub: #ifdef simplification
If we make SLUB_DEBUG depend on SYSFS then we can simplify some
#ifdefs and avoid others.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-05-02 00:27:13 +03:00
Christoph Lameter 0121c619d0 slub: Whitespace cleanup and use of strict_strtoul
Fix some issues with wrapping and use strict_strtoul to make parameter
passing from sysfs safer.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-05-02 00:26:31 +03:00
Balaji Rao 55e462b05b memcg: simple stats for memory resource controller
Implement trivial statistics for the memory resource controller.

Signed-off-by: Balaji Rao <balajirrao@gmail.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01 08:04:02 -07:00
Randy Dunlap c85d194bfd docbook: fix vmalloc missing parameter notation
Fix vmalloc kernel-doc warning:

Warning(linux-2.6.25-git14//mm/vmalloc.c:555): No description found for parameter 'caller'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01 08:03:59 -07:00
Roman Zippel f8bd2258e2 remove div_long_long_rem
x86 is the only arch right now, which provides an optimized for
div_long_long_rem and it has the downside that one has to be very careful that
the divide doesn't overflow.

The API is a little akward, as the arguments for the unsigned divide are
signed.  The signed version also doesn't handle a negative divisor and
produces worse code on 64bit archs.

There is little incentive to keep this API alive, so this converts the few
users to the new API.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01 08:03:58 -07:00
Andrew Morton 5167464446 revert "memory hotplug: allocate usemap on the section with pgdat"
This:

commit 86f6dae137
Author: Yasunori Goto <y-goto@jp.fujitsu.com>
Date:   Mon Apr 28 02:13:33 2008 -0700

    memory hotplug: allocate usemap on the section with pgdat

    Usemaps are allocated on the section which has pgdat by this.

    Because usemap size is very small, many other sections usemaps are allocated
    on only one page.  If a section has usemap, it can't be removed until removing
    other sections.  This dependency is not desirable for memory removing.

    Pgdat has similar feature.  When a section has pgdat area, it must be the last
    section for removing on the node.  So, if section A has pgdat and section B
    has usemap for section A, Both sections can't be removed due to dependency
    each other.

    To solve this issue, this patch collects usemap on same section with pgdat.
    If other sections doesn't have any dependency, this section will be able to be
    removed finally.

    Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
    Cc: Badari Pulavarty <pbadari@us.ibm.com>
    Cc: Yinghai Lu <yhlu.kernel@gmail.com>
    Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

broke davem's sparc64 bootup.  Revert it while we work out what went wrong.

Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:55 -07:00
Nick Piggin 3a902c5f68 mm: fix warning on memory offline
KAMEZAWA Hiroyuki found a warning message in the buffer dirtying code that
is coming from page migration caller.

WARNING: at fs/buffer.c:720 __set_page_dirty+0x330/0x360()
Call Trace:
 [<a000000100015220>] show_stack+0x80/0xa0
 [<a000000100015270>] dump_stack+0x30/0x60
 [<a000000100089ed0>] warn_on_slowpath+0x90/0xe0
 [<a0000001001f8b10>] __set_page_dirty+0x330/0x360
 [<a0000001001ffb90>] __set_page_dirty_buffers+0xd0/0x280
 [<a00000010012fec0>] set_page_dirty+0xc0/0x260
 [<a000000100195670>] migrate_page_copy+0x5d0/0x5e0
 [<a000000100197840>] buffer_migrate_page+0x2e0/0x3c0
 [<a000000100195eb0>] migrate_pages+0x770/0xe00

What was happening is that migrate_page_copy wants to transfer the PG_dirty
bit from old page to new page, so what it would do is set_page_dirty(newpage).
However set_page_dirty() is used to set the entire page dirty, wheras in
this case, only part of the page was dirty, and it also was not uptodate.

Marking the whole page dirty with set_page_dirty would lead to corruption or
unresolvable conditions -- a dirty && !uptodate page and dirty && !uptodate
buffers.

Possibly we could just ClearPageDirty(oldpage); SetPageDirty(newpage);
however in the interests of keeping the change minimal...

Signed-off-by: Nick Piggin <npiggin@suse.de>
Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:55 -07:00
Harvey Harrison d40cee245f mm: remove remaining __FUNCTION__ occurrences
__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:53 -07:00
Thomas Gleixner 3ac7fe5a4a infrastructure to debug (dynamic) objects
We can see an ever repeating problem pattern with objects of any kind in the
kernel:

1) freeing of active objects
2) reinitialization of active objects

Both problems can be hard to debug because the crash happens at a point where
we have no chance to decode the root cause anymore.  One problem spot are
kernel timers, where the detection of the problem often happens in interrupt
context and usually causes the machine to panic.

While working on a timer related bug report I had to hack specialized code
into the timer subsystem to get a reasonable hint for the root cause.  This
debug hack was fine for temporary use, but far from a mergeable solution due
to the intrusiveness into the timer code.

The code further lacked the ability to detect and report the root cause
instantly and keep the system operational.

Keeping the system operational is important to get hold of the debug
information without special debugging aids like serial consoles and special
knowledge of the bug reporter.

The problems described above are not restricted to timers, but timers tend to
expose it usually in a full system crash.  Other objects are less explosive,
but the symptoms caused by such mistakes can be even harder to debug.

Instead of creating specialized debugging code for the timer subsystem a
generic infrastructure is created which allows developers to verify their code
and provides an easy to enable debug facility for users in case of trouble.

The debugobjects core code keeps track of operations on static and dynamic
objects by inserting them into a hashed list and sanity checking them on
object operations and provides additional checks whenever kernel memory is
freed.

The tracked object operations are:
- initializing an object
- adding an object to a subsystem list
- deleting an object from a subsystem list

Each operation is sanity checked before the operation is executed and the
subsystem specific code can provide a fixup function which allows to prevent
the damage of the operation.  When the sanity check triggers a warning message
and a stack trace is printed.

The list of operations can be extended if the need arises.  For now it's
limited to the requirements of the first user (timers).

The core code enqueues the objects into hash buckets.  The hash index is
generated from the address of the object to simplify the lookup for the check
on kfree/vfree.  Each bucket has it's own spinlock to avoid contention on a
global lock.

The debug code can be compiled in without being active.  The runtime overhead
is minimal and could be optimized by asm alternatives.  A kernel command line
option enables the debugging code.

Thanks to Ingo Molnar for review, suggestions and cleanup patches.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Greg KH <greg@kroah.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:53 -07:00
Miklos Szeredi fc3ba692a4 mm: Add NR_WRITEBACK_TEMP counter
Fuse will use temporary buffers to write back dirty data from memory mappings
(normal writes are done synchronously).  This is needed, because there cannot
be any guarantee about the time in which a write will complete.

By using temporary buffers, from the MM's point if view the page is written
back immediately.  If the writeout was due to memory pressure, this
effectively migrates data from a full zone to a less full zone.

This patch adds a new counter (NR_WRITEBACK_TEMP) for the number of pages used
as temporary buffers.

[Lee.Schermerhorn@hp.com: add vmstat_text for NR_WRITEBACK_TEMP]
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:50 -07:00
Miklos Szeredi dd5656e59c mm: bdi: export bdi_writeout_inc()
Fuse needs this for writable mmap support.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:50 -07:00
Miklos Szeredi e4ad08fe64 mm: bdi: add separate writeback accounting capability
Add a new BDI capability flag: BDI_CAP_NO_ACCT_WB.  If this flag is
set, then don't update the per-bdi writeback stats from
test_set_page_writeback() and test_clear_page_writeback().

Misc cleanups:

 - convert bdi_cap_writeback_dirty() and friends to static inline functions
 - create a flag that includes all three dirty/writeback related flags,
   since almst all users will want to have them toghether

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:50 -07:00
Miklos Szeredi 76f1418b48 mm: bdi: move statistics to debugfs
Move BDI statistics to debugfs:

   /sys/kernel/debug/bdi/<bdi>/stats

Use postcore_initcall() to initialize the sysfs class and debugfs,
because debugfs is initialized in core_initcall().

Update descriptions in ABI documentation.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:50 -07:00
Peter Zijlstra a42dde0415 mm: bdi: allow setting a maximum for the bdi dirty limit
Add "max_ratio" to /sys/class/bdi.  This indicates the maximum percentage of
the global dirty threshold allocated to this bdi.

[mszeredi@suse.cz]

 - fix parsing in max_ratio_store().
 - export bdi_set_max_ratio() to modules
 - limit bdi_dirty with bdi->max_ratio
 - document new sysfs attribute

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:50 -07:00
Peter Zijlstra 189d3c4a94 mm: bdi: allow setting a minimum for the bdi dirty limit
Under normal circumstances each device is given a part of the total write-back
cache that relates to its current avg writeout speed in relation to the other
devices.

min_ratio - allows one to assign a minimum portion of the write-back cache to
a particular device.  This is useful in situations where you might want to
provide a minimum QoS.  (One request for this feature came from flash based
storage people who wanted to avoid writing out at all costs - they of course
needed some pdflush hacks as well)

max_ratio - allows one to assign a maximum portion of the dirty limit to a
particular device.  This is useful in situations where you want to avoid one
device taking all or most of the write-back cache.  Eg.  an NFS mount that is
prone to get stuck, or a FUSE mount which you don't trust to play fair.

Add "min_ratio" to /sys/class/bdi.  This indicates the minimum percentage of
the global dirty threshold allocated to this bdi.

[mszeredi@suse.cz]

 - fix parsing in min_ratio_store()
 - document new sysfs attribute

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:50 -07:00
Peter Zijlstra cf0ca9fe5d mm: bdi: export BDI attributes in sysfs
Provide a place in sysfs (/sys/class/bdi) for the backing_dev_info object.
This allows us to see and set the various BDI specific variables.

In particular this properly exposes the read-ahead window for all relevant
users and /sys/block/<block>/queue/read_ahead_kb should be deprecated.

With patient help from Kay Sievers and Greg KH

[mszeredi@suse.cz]

 - split off NFS and FUSE changes into separate patches
 - document new sysfs attributes under Documentation/ABI
 - do bdi_class_init as a core_initcall, otherwise the "default" BDI
   won't be initialized
 - remove bdi_init_fmt macro, it's not used very much

[akpm@linux-foundation.org: fix ia64 warning]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Greg KH <greg@kroah.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:49 -07:00
KOSAKI Motohiro 41b25a3784 /proc/pagetypeinfo: fix output for memoryless nodes
on memoryless node, /proc/pagetypeinfo is displayed slightly funny output.
this patch fix it.

output example (header is outputed, but no data is outputed)
--------------------------------------------------------------
Page block order: 14
Pages per block:  16384

Free pages count per migrate type at order       0      1      2      3      4      5    \
  6      7      8      9     10     11     12     13     14     15     16

Number of blocks type     Unmovable  Reclaimable      Movable      Reserve      Isolate
Page block order: 14
Pages per block:  16384

Free pages count per migrate type at order       0      1      2      3      4      5    \
  6      7      8      9     10     11     12     13     14     15     16

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:30 -07:00
Denis V. Lunev 3d71f86f4d mm: use non-racy method for /proc/swaps creation
Use proc_create() to make sure that ->proc_fops be setup before gluing PDE to
main tree.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:20 -07:00
Matt Helsley 925d1c401f procfs task exe symlink
The kernel implements readlink of /proc/pid/exe by getting the file from
the first executable VMA.  Then the path to the file is reconstructed and
reported as the result.

Because of the VMA walk the code is slightly different on nommu systems.
This patch avoids separate /proc/pid/exe code on nommu systems.  Instead of
walking the VMAs to find the first executable file-backed VMA we store a
reference to the exec'd file in the mm_struct.

That reference would prevent the filesystem holding the executable file
from being unmounted even after unmapping the VMAs.  So we track the number
of VM_EXECUTABLE VMAs and drop the new reference when the last one is
unmapped.  This avoids pinning the mounted filesystem.

[akpm@linux-foundation.org: improve comments]
[yamamoto@valinux.co.jp: fix dup_mmap]
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: David Howells <dhowells@redhat.com>
Cc:"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:17 -07:00
Nadia Derbey 0c40ba4fd6 ipc: define the slab_memory_callback priority as a constant
This is a trivial patch that defines the priority of slab_memory_callback in
the callback chain as a constant.  This is to prepare for next patch in the
series.

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Mingming Cao <cmm@us.ibm.com>
Cc: Pierre Peiffer <pierre.peiffer@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:12 -07:00
Li Zefan 1faf8e40a8 memcg: remove redundant initialization in mem_cgroup_create()
*mem has been zeroed, that means mem->info has already been filled with 0.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:11 -07:00
KAMEZAWA Hiroyuki 3332794878 memcgroup: use vmalloc for mem_cgroup allocation
On ia64, this kmalloc() requires order-4 pages.  But this is not necessary to
be physically contiguous.  For big mem_cgroup, vmalloc is better.  For small
ones, kmalloc is used.

[akpm@linux-foundation.org: simplification]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:11 -07:00
Balbir Singh 4a56d02e34 memcgroup: make the memory controller more desktop responsive
This patch makes the memory controller more responsive on my desktop.

1. Set all cached pages as inactive.  We were by default marking all pages
   as active, thus forcing us to go through two passes for reclaiming pages

2. Remove congestion_wait(), since we already have that logic in
   do_try_to_free_pages()

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:11 -07:00
KAMEZAWA Hiroyuki 3eae90c3cd memcg: remove redundant function calls
remove_list/add_list uses page_cgroup_zoneinfo() in it.

So, it's called twice before and after lock.

	mz = page_cgroup_zoneinfo();
	lock();
	mz = page_cgroup_zoneinfo();
	....
	unlock();

And address of mz never changes.

This is not good. This patch fixes this behavior.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:10 -07:00
Pavel Emelyanov 29f2a4dac8 memcgroup: implement failcounter reset
This is a very common requirement from people using the resource accounting
facilities (not only memcgroup but also OpenVZ beancounters).  They want to
put the cgroup in an initial state without re-creating it.

For example after re-configuring a group people want to observe how this new
configuration fits the group needs without saving the previous failcnt value.

Merge two resets into one mem_cgroup_reset() function to demonstrate how
multiplexing work.

Besides, I have plans to move the files, that correspond to res_counter to the
res_counter.c file and somehow "import" them into controller.  I don't know
how to make it gracefully yet, but merging resets of max_usage and failcnt in
one function will be there for sure.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:10 -07:00
Pavel Emelyanov 85cc59db12 memcgroup: use triggers in force_empty and max_usage files
These two files are essentially event callbacks.  They do not care about the
contents of the string, but only about the fact of the write itself.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:10 -07:00
Balbir Singh b6ac57d50a memcgroup: move memory controller allocations to their own slabs
Move the memory controller data structure page_cgroup to its own slab cache.
It saves space on the system, allocations are not necessarily pushed to order
of 2 and should provide performance benefits.  Users who disable the memory
controller can also double check that the memory controller is not allocating
page_cgroup's.

NOTE: Hugh Dickins brought up the issue of whether we want to mark page_cgroup
as __GFP_MOVABLE or __GFP_RECLAIMABLE.  I don't think there is an easy answer
at the moment.  page_cgroup's are associated with user pages, they can be
reclaimed once the user page has been reclaimed, so it might make sense to
mark them as __GFP_RECLAIMABLE.  For now, I am leaving the marking to default
values that the slab allocator uses.

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:10 -07:00
Pavel Emelyanov c84872e168 memcgroup: add the max_usage member on the res_counter
This field is the maximal value of the usage one since the counter creation
(or since the latest reset).

To reset this to the usage value simply write anything to the appropriate
cgroup file.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:10 -07:00
Balbir Singh cf475ad28a cgroups: add an owner to the mm_struct
Remove the mem_cgroup member from mm_struct and instead adds an owner.

This approach was suggested by Paul Menage.  The advantage of this approach
is that, once the mm->owner is known, using the subsystem id, the cgroup
can be determined.  It also allows several control groups that are
virtually grouped by mm_struct, to exist independent of the memory
controller i.e., without adding mem_cgroup's for each controller, to
mm_struct.

A new config option CONFIG_MM_OWNER is added and the memory resource
controller selects this config option.

This patch also adds cgroup callbacks to notify subsystems when mm->owner
changes.  The mm_cgroup_changed callback is called with the task_lock() of
the new task held and is called just prior to changing the mm->owner.

I am indebted to Paul Menage for the several reviews of this patchset and
helping me make it lighter and simpler.

This patch was tested on a powerpc box, it was compiled with both the
MM_OWNER config turned on and off.

After the thread group leader exits, it's moved to init_css_state by
cgroup_exit(), thus all future charges from runnings threads would be
redirected to the init_css_set's subsystem.

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: David Rientjes <rientjes@google.com>,
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: Paul Menage <menage@google.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:10 -07:00
Paul Menage c27e8818a0 CGroup API files: drop mem_cgroup_force_empty()
This function isn't needed - a NULL pointer in the cftype read function will
result in the same EINVAL response to userspace.

Signed-off-by: Paul Menage <menage@google.com>
Cc: "Li Zefan" <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:08 -07:00
Paul Menage c64745cf0f CGroup API files: use cgroup map for memcontrol stats file
Remove the seq_file boilerplate used to construct the memcontrol stats map,
and instead use the new map representation for cgroup control files

Signed-off-by: Paul Menage <menage@google.com>
Cc: "Li Zefan" <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:08 -07:00
Paul Menage 2c3daa722b CGroup API files: use read_u64 in memory controller
Update the memory controller to use read_u64 for its limit/usage/failcnt
control files, calling the new res_counter_read_u64() function.

Signed-off-by: Paul Menage <menage@google.com>
Cc: "Li Zefan" <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:08 -07:00
Nishanth Aravamudan 551883ae8c page allocator: explicitly retry hugepage allocations
Add __GFP_REPEAT to hugepage allocations.  Do so to not necessitate userspace
putting pressure on the VM by repeated echo's into /proc/sys/vm/nr_hugepages
to grow the pool.  With the previous patch to allow for large-order
__GFP_REPEAT attempts to loop for a bit (as opposed to indefinitely), this
increases the likelihood of getting hugepages when the system experiences (or
recently experienced) load.

Mel tested the patchset on an x86_32 laptop.  With the patches, it was easier
to use the proc interface to grow the hugepage pool.  The following is the
output of a script that grows the pool as much as possible running on
2.6.25-rc9.

Allocating hugepages test
-------------------------
Disabling OOM Killer for current test process
Starting page count: 0
Attempt 1: 57 pages Progress made with 57 pages
Attempt 2: 73 pages Progress made with 16 pages
Attempt 3: 74 pages Progress made with 1 pages
Attempt 4: 75 pages Progress made with 1 pages
Attempt 5: 77 pages Progress made with 2 pages

77 pages was the most it allocated but it took 5 attempts from userspace
to get it. With the 3 patches in this series applied,

Allocating hugepages test
-------------------------
Disabling OOM Killer for current test process
Starting page count: 0
Attempt 1: 75 pages Progress made with 75 pages
Attempt 2: 76 pages Progress made with 1 pages
Attempt 3: 79 pages Progress made with 3 pages

And 79 pages was the most it got. Your patches were able to allocate the
bulk of possible pages on the first attempt.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Tested-by: Mel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:05:58 -07:00
Nishanth Aravamudan a41f24ea9f page allocator: smarter retry of costly-order allocations
Because of page order checks in __alloc_pages(), hugepage (and similarly
large order) allocations will not retry unless explicitly marked
__GFP_REPEAT. However, the current retry logic is nearly an infinite
loop (or until reclaim does no progress whatsoever). For these costly
allocations, that seems like overkill and could potentially never
terminate. Mel observed that allowing current __GFP_REPEAT semantics for
hugepage allocations essentially killed the system. I believe this is
because we may continue to reclaim small orders of pages all over, but
never have enough to satisfy the hugepage allocation request. This is
clearly only a problem for large order allocations, of which hugepages
are the most obvious (to me).

Modify try_to_free_pages() to indicate how many pages were reclaimed.
Use that information in __alloc_pages() to eventually fail a large
__GFP_REPEAT allocation when we've reclaimed an order of pages equal to
or greater than the allocation's order. This relies on lumpy reclaim
functioning as advertised. Due to fragmentation, lumpy reclaim may not
be able to free up the order needed in one invocation, so multiple
iterations may be requred. In other words, the more fragmented memory
is, the more retry attempts __GFP_REPEAT will make (particularly for
higher order allocations).

This changes the semantics of __GFP_REPEAT subtly, but *only* for
allocations > PAGE_ALLOC_COSTLY_ORDER. With this patch, for those size
allocations, we will try up to some point (at least 1<<order reclaimed
pages), rather than forever (which is the case for allocations <=
PAGE_ALLOC_COSTLY_ORDER).

This change improves the /proc/sys/vm/nr_hugepages interface with a
follow-on patch that makes pool allocations use __GFP_REPEAT. Rather
than administrators repeatedly echo'ing a particular value into the
sysctl, and forcing reclaim into action manually, this change allows for
the sysctl to attempt a reasonable effort itself. Similarly, dynamic
pool growth should be more successful under load, as lumpy reclaim can
try to free up pages, rather than failing right away.

Choosing to reclaim only up to the order of the requested allocation
strikes a balance between not failing hugepage allocations and returning
to the caller when it's unlikely to every succeed. Because of lumpy
reclaim, if we have freed the order requested, hopefully it has been in
big chunks and those chunks will allow our allocation to succeed. If
that isn't the case after freeing up the current order, I don't think it
is likely to succeed in the future, although it is possible given a
particular fragmentation pattern.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Tested-by: Mel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:05:58 -07:00
Nishanth Aravamudan ab857d0938 mm: fix misleading __GFP_REPEAT related comments
The definition and use of __GFP_REPEAT, __GFP_NOFAIL and __GFP_NORETRY in the
core VM have somewhat differing comments as to their actual semantics.
Annoyingly, the flags definition has inline and header comments, which might
be interpreted as not being equivalent.  Just add references to the header
comments in the inline ones so they don't go out of sync in the future.  In
their use in __alloc_pages() clarify that the current implementation treats
low-order allocations and __GFP_REPEAT allocations as distinct cases.

To clarify, the flags' semantics are:

__GFP_NORETRY means try no harder than one run through __alloc_pages

__GFP_REPEAT means __GFP_NOFAIL

__GFP_NOFAIL means repeat forever

order <= PAGE_ALLOC_COSTLY_ORDER means __GFP_NOFAIL

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:05:58 -07:00
KAMEZAWA Hiroyuki 86051ca5ea mm: fix usemap initialization
usemap must be initialized only when pfn is within zone.  If not, it corrupts
memory.

And this patch also reduces the number of calls to set_pageblock_migratetype()
from
	(pfn & (pageblock_nr_pages -1)
to
	!(pfn & (pageblock_nr_pages-1)
it should be called once per pageblock.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Shi Weihua <shiwh@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:05:58 -07:00
Harvey Harrison 7b8ee84d89 mm: fix integer as NULL pointer warnings
mm/hugetlb.c:207:11: warning: Using plain integer as NULL pointer

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 17:29:18 -07:00
Linus Torvalds e97e386b12 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: pack objects denser
  slub: Calculate min_objects based on number of processors.
  slub: Drop DEFAULT_MAX_ORDER / DEFAULT_MIN_OBJECTS
  slub: Simplify any_slab_object checks
  slub: Make the order configurable for each slab cache
  slub: Drop fallback to page allocator method
  slub: Fallback to minimal order during slab page allocation
  slub: Update statistics handling for variable order slabs
  slub: Add kmem_cache_order_objects struct
  slub: for_each_object must be passed the number of objects in a slab
  slub: Store max number of objects in the page struct.
  slub: Dump list of objects not freed on kmem_cache_close()
  slub: free_list() cleanup
  slub: improve kmem_cache_destroy() error message
  slob: fix bug - when slob allocates "struct kmem_cache", it does not force alignment.
2008-04-28 14:08:56 -07:00
Adrian Bunk 1e5ad9a3b9 mm/memory_hotplug.c must #include "internal.h"
This patch fixes the following compile error caused by commit
0475327876 ("memory hotplug: register
section/node id to free"):

    CC      mm/memory_hotplug.o
  /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/memory_hotplug.c: In function ‘put_page_bootmem’:
  /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/memory_hotplug.c:82: error: implicit declaration of function ‘__free_pages_bootmem’
  /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/memory_hotplug.c: At top level:
  /home/bunk/linux/kernel-2.6/git/linux-2.6/mm/memory_hotplug.c:87: warning: no previous prototype for ‘register_page_bootmem_info_section’
  make[2]: *** [mm/memory_hotplug.o] Error 1

[ Andrew: "Argh.  The -mm-only memory-hotplug-add-removable-to-sysfs-
  to-show-memblock-removability.patch debugging patch adds that include
  so nobody hit this before. ]

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 13:44:29 -07:00
Michael Hennerich 4016a1390d mm/nommu.c: return 0 from kobjsize with invalid objects
Don't perform kobjsize operations on objects the kernel doesn't manage.

On Blackfin, drivers can get dma coherent memory by calling a function
dma_alloc_coherent(). We do this in nommu by configuring a chunk of uncached
memory at the top of memory.

Since we don't want the kernel to use the uncached memory, we lie to the
kernel, and tell it that it's max memory is between 0, and the start of the
uncached dma coherent section.

this all works well, until this memory gets exposed into userspace (with a
frame buffer), when you look at the process's maps, it shows the framebuf:

root:/proc> cat maps
[snip]
03f0ef00-03f34700 rw-p 00000000 1f:00 192        /dev/fb0
root:/proc>

This is outside the "normal" range for the kernel. When the kernel tries to
find the size of this object (when you run ps), it dies in nommu.c in
kobjsize.

BUG_ON(page->index >= MAX_ORDER);

since the page we are referring to is outside what the kernel thinks is it's
max valid memory.

root:~> while [ 1 ]; ps > /dev/null; done
kernel BUG at mm/nommu.c:119!
Kernel panic - not syncing: BUG!

We fixed this by adding a check to reject out of range object pointers as it
already does that for NULL pointers.

Signed-off-by: Michael Hennerich <Michael.Hennerich@analog.com>
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:26 -07:00
Dimitri Sivanich 468fd62ed9 vmstats: add cond_resched() to refresh_cpu_vm_stats()
We've found that it can take quite a bit of time (100's of usec) to get
through the zone loop in refresh_cpu_vm_stats().

Adding a cond_resched() to allow other threads to run in the non-preemptive
case.

Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:26 -07:00
Pavel Machek 2309f9e6fe mm/page_alloc.c: remove hand-coded get_order()
Remove hand-coded get_order() from page_alloc.c.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:26 -07:00
Li Zefan 97d87c9710 oom_kill: remove unused parameter in badness()
In commit 4c4a221489, we moved the
memcontroller-related code from badness() to select_bad_process(), so the
parameter 'mem' in badness() is unused now.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:26 -07:00
Yasunori Goto 0c0a4a517a memory hotplug: free memmaps allocated by bootmem
This patch is to free memmaps which is allocated by bootmem.

Freeing usemap is not necessary.  The pages of usemap may be necessary for
other sections.

If removing section is last section on the node, its section is the final user
of usemap page.  (usemaps are allocated on its section by previous patch.) But
it shouldn't be freed too, because the section must be logical offline state
which all pages are isolated against page allocater.  If it is freed, page
alloctor may use it which will be removed physically soon.  It will be
disaster.  So, this patch keeps it as it is.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:26 -07:00
Yasunori Goto 86f6dae137 memory hotplug: allocate usemap on the section with pgdat
Usemaps are allocated on the section which has pgdat by this.

Because usemap size is very small, many other sections usemaps are allocated
on only one page.  If a section has usemap, it can't be removed until removing
other sections.  This dependency is not desirable for memory removing.

Pgdat has similar feature.  When a section has pgdat area, it must be the last
section for removing on the node.  So, if section A has pgdat and section B
has usemap for section A, Both sections can't be removed due to dependency
each other.

To solve this issue, this patch collects usemap on same section with pgdat.
If other sections doesn't have any dependency, this section will be able to be
removed finally.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:25 -07:00
Yasunori Goto e70260aabe memory hotplug: make alloc_bootmem_section()
alloc_bootmem_section() can allocate specified section's area.  This is used
for usemap to keep same section with pgdat by later patch.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:25 -07:00
Yasunori Goto 9d99217a02 memory hotplug: align memmap to page size
To free memmap easier, this patch aligns it to page size.  Bootmem allocater
may mix some objects in one pages.  It's not good for freeing memmap of memory
hot-remove.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:25 -07:00
Yasunori Goto 0475327876 memory hotplug: register section/node id to free
This patch set is to free pages which is allocated by bootmem for
memory-hotremove.  Some structures of memory management are allocated by
bootmem.  ex) memmap, etc.

To remove memory physically, some of them must be freed according to
circumstance.  This patch set makes basis to free those pages, and free
memmaps.

Basic my idea is using remain members of struct page to remember information
of users of bootmem (section number or node id).  When the section is
removing, kernel can confirm it.  By this information, some issues can be
solved.

  1) When the memmap of removing section is allocated on other
     section by bootmem, it should/can be free.
  2) When the memmap of removing section is allocated on the
     same section, it shouldn't be freed. Because the section has to be
     logical memory offlined already and all pages must be isolated against
     page allocater. If it is freed, page allocator may use it which will
     be removed physically soon.
  3) When removing section has other section's memmap,
     kernel will be able to show easily which section should be removed
     before it for user. (Not implemented yet)
  4) When the above case 2), the page isolation will be able to check and skip
     memmap's page when logical memory offline (offline_pages()).
     Current page isolation code fails in this case because this page is
     just reserved page and it can't distinguish this pages can be
     removed or not. But, it will be able to do by this patch.
     (Not implemented yet.)
  5) The node information like pgdat has similar issues. But, this
     will be able to be solved too by this.
     (Not implemented yet, but, remembering node id in the pages.)

Fortunately, current bootmem allocator just keeps PageReserved flags,
and doesn't use any other members of page struct. The users of
bootmem doesn't use them too.

This patch:

This is to register information which is node or section's id.  Kernel can
distinguish which node/section uses the pages allcated by bootmem.  This is
basis for hot-remove sections or nodes.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:25 -07:00
Gerald Schaefer 7f2e9525ba hugetlbfs: common code update for s390
Huge ptes have a special type on s390 and cannot be handled with the standard
pte functions in certain cases, e.g.  because of a different location of the
invalid bit.  This patch adds some new architecture- specific functions to
hugetlb common code, as a prerequisite for the s390 large page support.

This won't affect other architectures in functionality, but I need to add some
new dummy inline functions to the headers.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:25 -07:00
Gerald Schaefer 8fe627ec5b hugetlbfs: add missing TLB flush to hugetlb_cow()
A cow break on a hugetlbfs page with page_count > 1 will set a new pte with
set_huge_pte_at(), w/o any tlb flush operation.  The old pte will remain in
the tlb and subsequent write access to the page will result in a page fault
loop, for as long as it may take until the tlb is flushed from somewhere else.
 This patch introduces an architecture-specific huge_ptep_clear_flush()
function, which is called before the the set_huge_pte_at() in hugetlb_cow().

ATTENTION: This is just a nop on all architectures for now, the s390
implementation will come with our large page patch later.  Other architectures
should define their own huge_ptep_clear_flush() if needed.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:25 -07:00
Lee Schermerhorn 71fe804b6d mempolicy: use struct mempolicy pointer in shmem_sb_info
This patch replaces the mempolicy mode, mode_flags, and nodemask in the
shmem_sb_info struct with a struct mempolicy pointer, initialized to NULL.
This removes dependency on the details of mempolicy from shmem.c and hugetlbfs
inode.c and simplifies the interfaces.

mpol_parse_str() in mempolicy.c is changed to return, via a pointer to a
pointer arg, a struct mempolicy pointer on success.  For MPOL_DEFAULT, the
returned pointer is NULL.  Further, mpol_parse_str() now takes a 'no_context'
argument that causes the input nodemask to be stored in the w.user_nodemask of
the created mempolicy for use when the mempolicy is installed in a tmpfs inode
shared policy tree.  At that time, any cpuset contextualization is applied to
the original input nodemask.  This preserves the previous behavior where the
input nodemask was stored in the superblock.  We can think of the returned
mempolicy as "context free".

Because mpol_parse_str() is now calling mpol_new(), we can remove from
mpol_to_str() the semantic checks that mpol_new() already performs.

Add 'no_context' parameter to mpol_to_str() to specify that it should format
the nodemask in w.user_nodemask for 'bind' and 'interleave' policies.

Change mpol_shared_policy_init() to take a pointer to a "context free" struct
mempolicy and to create a new, "contextualized" mempolicy using the mode,
mode_flags and user_nodemask from the input mempolicy.

  Note: we know that the mempolicy passed to mpol_to_str() or
  mpol_shared_policy_init() from a tmpfs superblock is "context free".  This
  is currently the only instance thereof.  However, if we found more uses for
  this concept, and introduced any ambiguity as to whether a mempolicy was
  context free or not, we could add another internal mode flag to identify
  context free mempolicies.  Then, we could remove the 'no_context' argument
  from mpol_to_str().

Added shmem_get_sbmpol() to return a reference counted superblock mempolicy,
if one exists, to pass to mpol_shared_policy_init().  We must add the
reference under the sb stat_lock to prevent races with replacement of the mpol
by remount.  This reference is removed in mpol_shared_policy_init().

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: another build fix]
[akpm@linux-foundation.org: yet another build fix]
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:25 -07:00
Lee Schermerhorn 3f226aa1cb mempolicy: support mpol=local tmpfs mount option
For tmpfs/shmem shared policies, MPOL_DEFAULT is not necessarily equivalent to
"local allocation".  Because shared policies are at the same "scope" level
[see Documentation/vm/numa_memory_policy.txt], as vma policies MPOL_DEFAULT
means "fall back to current task policy".

This patch extends the memory policy string parsing function to display
"local" for MPOL_PREFERRED + MPOL_F_LOCAL.  This allows one to specify local
allocation as the default policy for shared memory areas via the tmpfs mpol
mount option, regardless of the current task's policy.

Also, "local" is now displayed for this policy.  This patch allows us to
accept the same input format as the display.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:25 -07:00
Lee Schermerhorn 095f1fc4eb mempolicy: rework shmem mpol parsing and display
mm/shmem.c currently contains functions to parse and display memory policy
strings for the tmpfs 'mpol' mount option.  Move this to mm/mempolicy.c with
the rest of the mempolicy support.  With subsequent patches, we'll be able to
remove knowledge of the details [mode, flags, policy, ...] completely from
shmem.c

1) replace shmem_parse_mpol() in mm/shmem.c with mpol_parse_str() in
   mm/mempolicy.c.  Rework to use the policy_types[] array [used by
   mpol_to_str()] to look up mode by name.

2) use mpol_to_str() to format policy for shmem_show_mpol().  mpol_to_str()
   expects a pointer to a struct mempolicy, so temporarily construct one.
   This will be replaced with a reference to a struct mempolicy in the tmpfs
   superblock in a subsequent patch.

   NOTE 1: I changed mpol_to_str() to use a colon ':' rather than an equal
   sign '=' as the nodemask delimiter to match mpol_parse_str() and the
   tmpfs/shmem mpol mount option formatting that now uses mpol_to_str().  This
   is a user visible change to numa_maps, but then the addition of the mode
   flags already changed the display.  It makes sense to me to have the mounts
   and numa_maps display the policy in the same format.  However, if anyone
   objects strongly, I can pass the desired nodemask delimeter as an arg to
   mpol_to_str().

   Note 2: Like show_numa_map(), I don't check the return code from
   mpol_to_str().  I do use a longer buffer than the one provided by
   show_numa_map(), which seems to have sufficed so far.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:24 -07:00
Lee Schermerhorn 2291990ab3 mempolicy: clean-up mpol-to-str() mempolicy formatting
mpol-to-str() formats memory policies into printable strings.  Currently this
is only used to display "numa_maps".  A subsequent patch will use
mpol_to_str() for formatting tmpfs [shmem] mpol mount options, allowing us to
remove essentially duplicate code in mm/shmem.c.  This patch cleans up
mpol_to_str() generally and in preparation for that patch.

1) show_numa_maps() is not checking the return code from mpol_to_str().
   There's not a lot we can do in this context if mpol_to_str() did return the
   error [insufficient space in buffer].  Proposed "solution": just check,
   under DEBUG_VM, that callers are providing sufficient buffer space for the
   policy, flags, and a few nodes.  This way, we'll get some display.
   show_numa_maps() is providing a 50-byte buffer, so it won't trip this
   check.  50-bytes should be sufficient unless one has a large number of
   nodes in a very sparse nodemask.

2) The display of the new mode flags ["static" & "relative"] was set up to
   display multiple flags, separated by a "bar" '|'.  However, this support is
   incomplete--e.g., need_bar was never incremented; and currently, these two
   flags are mutually exclusive.  So remove the "bar" support, for now, and
   only display one flag.

3) Use snprint() to format flags, so as not to overflow the buffer.  Not
   that it's ever happed, AFAIK.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:24 -07:00
Lee Schermerhorn fc36b8d3d8 mempolicy: use MPOL_F_LOCAL to Indicate Preferred Local Policy
Now that we're using "preferred local" policy for system default, we need to
make this as fast as possible.  Because of the variable size of the mempolicy
structure [based on size of nodemasks], the preferred_node may be in a
different cacheline from the mode.  This can result in accessing an extra
cacheline in the normal case of system default policy.  Suspect this is the
cause of an observed 2-3% slowdown in page fault testing relative to kernel
without this patch series.

To alleviate this, use an internal mode flag, MPOL_F_LOCAL in the mempolicy
flags member which is guaranteed [?] to be in the same cacheline as the mode
itself.

Verified that reworked mempolicy now performs slightly better on 25-rc8-mm1
for both anon and shmem segments with system default and vma [preferred local]
policy.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:24 -07:00
Lee Schermerhorn 53f2556b67 mempolicy: mPOL_PREFERRED cleanups for "local allocation"
Here are a couple of "cleanups" for MPOL_PREFERRED behavior when
v.preferred_node < 0 -- i.e., "local allocation":

1)  [do_]get_mempolicy() calls the now renamed get_policy_nodemask()
    to fetch the nodemask associated with a policy.  Currently,
    get_policy_nodemask() returns the set of nodes with memory, when
    the policy 'mode' is 'PREFERRED, and the preferred_node is < 0.
    Change to return an empty nodemask, as this is what was specified
    to achieve "local allocation".

2)  When a task is moved into a [new] cpuset, mpol_rebind_policy() is
    called to adjust any task and vma policy nodes to be valid in the
    new cpuset.  However, when the policy is MPOL_PREFERRED, and the
    preferred_node is <0, no rebind is necessary.  The "local allocation"
    indication is valid in any cpuset.  Existing code will "do the right
    thing" because node_remap() will just return the argument node when
    it is outside of the valid range of node ids.  However, I think it is
    clearer and cleaner to skip the remap explicitly in this case.

3)  mpol_to_str() produces a printable, "human readable" string from a
    struct mempolicy.  For MPOL_PREFERRED with preferred_node <0,  show
    "local", as this indicates local allocation, as the task migrates
    among nodes.  Note that this matches the usage of "local allocation"
    in libnuma() and numactl.  Without this change, I believe that node_set()
    [via set_bit()] will set bit 31, resulting in a misleading display.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:24 -07:00
Lee Schermerhorn bea904d54d mempolicy: use MPOL_PREFERRED for system-wide default policy
Currently, when one specifies MPOL_DEFAULT via a NUMA memory policy API
[set_mempolicy(), mbind() and internal versions], the kernel simply installs a
NULL struct mempolicy pointer in the appropriate context: task policy, vma
policy, or shared policy.  This causes any use of that policy to "fall back"
to the next most specific policy scope.

The only use of MPOL_DEFAULT to mean "local allocation" is in the system
default policy.  This requires extra checks/cases for MPOL_DEFAULT in many
mempolicy.c functions.

There is another, "preferred" way to specify local allocation via the APIs.
That is using the MPOL_PREFERRED policy mode with an empty nodemask.
Internally, the empty nodemask gets converted to a preferred_node id of '-1'.
All internal usage of MPOL_PREFERRED will convert the '-1' to the id of the
node local to the cpu where the allocation occurs.

System default policy, except during boot, is hard-coded to "local
allocation".  By using the MPOL_PREFERRED mode with a negative value of
preferred node for system default policy, MPOL_DEFAULT will never occur in the
'policy' member of a struct mempolicy.  Thus, we can remove all checks for
MPOL_DEFAULT when converting policy to a node id/zonelist in the allocation
paths.

In slab_node() return local node id when policy pointer is NULL.  No need to
set a pol value to take the switch default.  Replace switch default with
BUG()--i.e., shouldn't happen.

With this patch MPOL_DEFAULT is only used in the APIs, including internal
calls to do_set_mempolicy() and in the display of policy in
/proc/<pid>/numa_maps.  It always means "fall back" to the the next most
specific policy scope.  This simplifies the description of memory policies
quite a bit, with no visible change in behavior.

get_mempolicy() continues to return MPOL_DEFAULT and an empty nodemask when
the requested policy [task or vma/shared] is NULL.  These are the values one
would supply via set_mempolicy() or mbind() to achieve that condition--default
behavior.

This patch updates Documentation to reflect this change.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:24 -07:00
Lee Schermerhorn 52cd3b0740 mempolicy: rework mempolicy Reference Counting [yet again]
After further discussion with Christoph Lameter, it has become clear that my
earlier attempts to clean up the mempolicy reference counting were a bit of
overkill in some areas, resulting in superflous ref/unref in what are usually
fast paths.  In other areas, further inspection reveals that I botched the
unref for interleave policies.

A separate patch, suitable for upstream/stable trees, fixes up the known
errors in the previous attempt to fix reference counting.

This patch reworks the memory policy referencing counting and, one hopes,
simplifies the code.  Maybe I'll get it right this time.

See the update to the numa_memory_policy.txt document for a discussion of
memory policy reference counting that motivates this patch.

Summary:

Lookup of mempolicy, based on (vma, address) need only add a reference for
shared policy, and we need only unref the policy when finished for shared
policies.  So, this patch backs out all of the unneeded extra reference
counting added by my previous attempt.  It then unrefs only shared policies
when we're finished with them, using the mpol_cond_put() [conditional put]
helper function introduced by this patch.

Note that shmem_swapin() calls read_swap_cache_async() with a dummy vma
containing just the policy.  read_swap_cache_async() can call alloc_page_vma()
multiple times, so we can't let alloc_page_vma() unref the shared policy in
this case.  To avoid this, we make a copy of any non-null shared policy and
remove the MPOL_F_SHARED flag from the copy.  This copy occurs before reading
a page [or multiple pages] from swap, so the overhead should not be an issue
here.

I introduced a new static inline function "mpol_cond_copy()" to copy the
shared policy to an on-stack policy and remove the flags that would require a
conditional free.  The current implementation of mpol_cond_copy() assumes that
the struct mempolicy contains no pointers to dynamically allocated structures
that must be duplicated or reference counted during copy.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:24 -07:00
Lee Schermerhorn aab0b1029f mempolicy: mark shared policies for unref
As part of yet another rework of mempolicy reference counting, we want to be
able to identify shared policies efficiently, because they have an extra ref
taken on lookup that needs to be removed when we're finished using the policy.

  Note:  the extra ref is required because the policies are
  shared between tasks/processes and can be changed/freed
  by one task while another task is using them--e.g., for
  page allocation.

Building on David Rientjes mempolicy "mode flags" enhancement, this patch
indicates a "shared" policy by setting a new MPOL_F_SHARED flag in the flags
member of the struct mempolicy added by David.  MPOL_F_SHARED, and any future
"internal mode flags" are reserved from bit zero up, as they will never be
passed in the upper bits of the mode argument of a mempolicy API.

I set the MPOL_F_SHARED flag when the policy is installed in the shared policy
rb-tree.  Don't need/want to clear the flag when removing from the tree as the
mempolicy is freed [unref'd] internally to the sp_delete() function.  However,
a task could hold another reference on this mempolicy from a prior lookup.  We
need the MPOL_F_SHARED flag to stay put so that any tasks holding a ref will
unref, eventually freeing, the mempolicy.

A later patch in this series will introduce a function to conditionally unref
[mpol_free] a policy.  The MPOL_F_SHARED flag is one reason [currently the
only reason] to unref/free a policy via the conditional free.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:24 -07:00
Lee Schermerhorn 45c4745af3 mempolicy: rename struct mempolicy 'policy' member to 'mode'
The terms 'policy' and 'mode' are both used in various places to describe the
semantics of the value stored in the 'policy' member of struct mempolicy.
Furthermore, the term 'policy' is used to refer to that member, to the entire
struct mempolicy and to the more abstract concept of the tuple consisting of a
"mode" and an optional node or set of nodes.  Recently, we have added "mode
flags" that are passed in the upper bits of the 'mode' [or sometimes,
'policy'] member of the numa APIs.

I'd like to resolve this confusion, which perhaps only exists in my mind, by
renaming the 'policy' member to 'mode' throughout, and fixing up the
Documentation.  Man pages will be updated separately.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:24 -07:00
Lee Schermerhorn ae4d8c16aa mempolicy: fixup Fallback for Default Shmem Policy
get_vma_policy() is not handling fallback to task policy correctly when the
get_policy() vm_op returns NULL.  The NULL overwrites the 'pol' variable that
was holding the fallback task mempolicy.  So, it was falling back directly to
system default policy.

Fix get_vma_policy() to use only non-NULL policy returned from the vma
get_policy op.

shm_get_policy() was falling back to current task's mempolicy if the "backing
file system" [tmpfs vs hugetlbfs] does not support the get_policy vm_op and
the vma policy is null.  This is incorrect for show_numa_maps() which is
likely querying the numa_maps of some task other than current.  Remove this
fallback.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:24 -07:00
Lee Schermerhorn f4e53d910b mempolicy: write lock mmap_sem while changing task mempolicy
A read of /proc/<pid>/numa_maps holds the target task's mmap_sem for read
while examining each vma's mempolicy.  A vma's mempolicy can fall back to the
task's policy.  However, the task could be changing it's task policy and free
the one that the show_numa_maps() is examining.

To prevent this, grab the mmap_sem for write when updating task mempolicy.
Pointed out to me by Christoph Lameter and extracted and reworked from
Christoph's alternative mempol reference counting patch.

This is analogous to the way that do_mbind() and do_get_mempolicy() prevent
races between task's sharing an mm_struct [a.k.a.  threads] setting and
querying a mempolicy for a particular address.

Note: this is necessary, but not sufficient, to allow us to stop taking an
extra reference on "other task's mempolicy" in get_vma_policy.  Subsequent
patches will complete this update, allowing us to simplify the tests for
whether we need to unref a mempolicy at various points in the code.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:23 -07:00
Lee Schermerhorn 846a16bf0f mempolicy: rename mpol_copy to mpol_dup
This patch renames mpol_copy() to mpol_dup() because, well, that's what it
does.  Like, e.g., strdup() for strings, mpol_dup() takes a pointer to an
existing mempolicy, allocates a new one and copies the contents.

In a later patch, I want to use the name mpol_copy() to copy the contents from
one mempolicy to another like, e.g., strcpy() does for strings.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:23 -07:00
Lee Schermerhorn f0be3d32b0 mempolicy: rename mpol_free to mpol_put
This is a change that was requested some time ago by Mel Gorman.  Makes sense
to me, so here it is.

Note: I retain the name "mpol_free_shared_policy()" because it actually does
free the shared_policy, which is NOT a reference counted object.  However, ...

The mempolicy object[s] referenced by the shared_policy are reference counted,
so mpol_put() is used to release the reference held by the shared_policy.  The
mempolicy might not be freed at this time, because some task attached to the
shared object associated with the shared policy may be in the process of
allocating a page based on the mempolicy.  In that case, the task performing
the allocation will hold a reference on the mempolicy, obtained via
mpol_shared_policy_lookup().  The mempolicy will be freed when all tasks
holding such a reference have called mpol_put() for the mempolicy.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:23 -07:00
Adam Litke 3b11630063 Subject: [PATCH] hugetlb: vmstat events for huge page allocations
Allocating huge pages directly from the buddy allocator is not guaranteed to
succeed.  Success depends on several factors (such as the amount of physical
memory available and the level of fragmentation).  With the addition of
dynamic hugetlb pool resizing, allocations can occur much more frequently.
For these reasons it is desirable to keep track of huge page allocation
successes and failures.

Add two new vmstat entries to track huge page allocations that succeed and
fail.  The presence of the two entries is contingent upon CONFIG_HUGETLB_PAGE
being enabled.

[akpm@linux-foundation.org: reduced ifdeffery]
Signed-off-by: Adam Litke <agl@us.ibm.com>
Signed-off-by: Eric Munson <ebmunson@us.ibm.com>
Tested-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Andy Whitcroft <apw@shadowen.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:23 -07:00
Nick Piggin 70688e4dd1 xip: support non-struct page backed memory
Convert XIP to support non-struct page backed memory, using VM_MIXEDMAP for
the user mappings.

This requires the get_xip_page API to be changed to an address based one.
Improve the API layering a little bit too, while we're here.

This is required in order to support XIP filesystems on memory that isn't
backed with struct page (but memory with struct page is still supported too).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Carsten Otte <cotte@de.ibm.com>
Cc: Jared Hulbert <jaredeh@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:23 -07:00
Nick Piggin 423bad6004 mm: add vm_insert_mixed
vm_insert_mixed will insert either a raw pfn or a refcounted struct page into
the page tables, depending on whether vm_normal_page() will return the page or
not.  With the introduction of the new pte bit, this is now a too tricky for
drivers to be doing themselves.

filemap_xip uses this in a subsequent patch.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Jared Hulbert <jaredeh@gmail.com>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:23 -07:00
Nick Piggin 7e675137a8 mm: introduce pte_special pte bit
s390 for one, cannot implement VM_MIXEDMAP with pfn_valid, due to their memory
model (which is more dynamic than most).  Instead, they had proposed to
implement it with an additional path through vm_normal_page(), using a bit in
the pte to determine whether or not the page should be refcounted:

vm_normal_page()
{
	...
        if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
                if (vma->vm_flags & VM_MIXEDMAP) {
#ifdef s390
			if (!mixedmap_refcount_pte(pte))
				return NULL;
#else
                        if (!pfn_valid(pfn))
                                return NULL;
#endif
                        goto out;
                }
	...
}

This is fine, however if we are allowed to use a bit in the pte to determine
refcountedness, we can use that to _completely_ replace all the vma based
schemes.  So instead of adding more cases to the already complex vma-based
scheme, we can have a clearly seperate and simple pte-based scheme (and get
slightly better code generation in the process):

vm_normal_page()
{
#ifdef s390
	if (!mixedmap_refcount_pte(pte))
		return NULL;
	return pte_page(pte);
#else
	...
#endif
}

And finally, we may rather make this concept usable by any architecture rather
than making it s390 only, so implement a new type of pte state for this.
Unfortunately the old vma based code must stay, because some architectures may
not be able to spare pte bits.  This makes vm_normal_page a little bit more
ugly than we would like, but the 2 cases are clearly seperate.

So introduce a pte_special pte state, and use it in mm/memory.c.  It is
currently a noop for all architectures, so this doesn't actually result in any
compiled code changes to mm/memory.o.

BTW:
I haven't put vm_normal_page() into arch code as-per an earlier suggestion.
The reason is that, regardless of where vm_normal_page is actually
implemented, the *abstraction* is still exactly the same. Also, while it
depends on whether the architecture has pte_special or not, that is the
only two possible cases, and it really isn't an arch specific function --
the role of the arch code should be to provide primitive functions and
accessors with which to build the core code; pte_special does that. We do
not want architectures to know or care about vm_normal_page itself, and
we definitely don't want them being able to invent something new there
out of sight of mm/ code. If we made vm_normal_page an arch function, then
we have to make vm_insert_mixed (next patch) an arch function too. So I
don't think moving it to arch code fundamentally improves any abstractions,
while it does practically make the code more difficult to follow, for both
mm and arch developers, and easier to misuse.

[akpm@linux-foundation.org: build fix]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Carsten Otte <cotte@de.ibm.com>
Cc: Jared Hulbert <jaredeh@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:23 -07:00
Jared Hulbert b379d79019 mm: introduce VM_MIXEDMAP
This series introduces some important infrastructure work.  The overall result
is that:

1. We now support XIP backed filesystems using memory that have no
   struct page allocated to them. And patches 6 and 7 actually implement
   this for s390.

   This is pretty important in a number of cases. As far as I understand,
   in the case of virtualisation (eg. s390), each guest may mount a
   readonly copy of the same filesystem (eg. the distro). Currently,
   guests need to allocate struct pages for this image. So if you have
   100 guests, you already need to allocate more memory for the struct
   pages than the size of the image. I think. (Carsten?)

   For other (eg. embedded) systems, you may have a very large non-
   volatile filesystem. If you have to have struct pages for this, then
   your RAM consumption will go up proportionally to fs size. Even
   though it is just a small proportion, the RAM can be much more costly
   eg in terms of power, so every KB less that Linux uses makes it more
   attractive to a lot of these guys.

2. VM_MIXEDMAP allows us to support mappings where you actually do want
   to refcount _some_ pages in the mapping, but not others, and support
   COW on arbitrary (non-linear) mappings. Jared needs this for his NVRAM
   filesystem in progress. Future iterations of this filesystem will
   most likely want to migrate pages between pagecache and XIP backing,
   which is where the requirement for mixed (some refcounted, some not)
   comes from.

3. pte_special also has a peripheral usage that I need for my lockless
   get_user_pages patch. That was shown to speed up "oltp" on db2 by
   10% on a 2 socket system, which is kind of significant because they
   scrounge for months to try to find 0.1% improvement on these
   workloads. I'm hoping we might finally be faster than AIX on
   pSeries with this :). My reference to lockless get_user_pages is not
   meant to justify this patchset (which doesn't include lockless gup),
   but just to show that pte_special is not some s390 specific thing that
   should be hidden in arch code or xip code: I definitely want to use it
   on at least x86 and powerpc as well.

This patch:

Introduce a new type of mapping, VM_MIXEDMAP.  This is unlike VM_PFNMAP in
that it can support COW mappings of arbitrary ranges including ranges without
struct page *and* ranges with a struct page that we actually want to refcount
(PFNMAP can only support COW in those cases where the un-COW-ed translations
are mapped linearly in the virtual address, and can only support non
refcounted ranges).

VM_MIXEDMAP achieves this by refcounting all pfn_valid pages, and not
refcounting !pfn_valid pages (which is not an option for VM_PFNMAP, because it
needs to avoid refcounting pfn_valid pages eg.  for /dev/mem mappings).

Signed-off-by: Jared Hulbert <jaredeh@gmail.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Carsten Otte <cotte@de.ibm.com>
Cc: Jared Hulbert <jaredeh@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:22 -07:00
Christoph Lameter e20b8cca76 PAGEFLAGS_EXTENDED and separate page flags for Head and Tail
Having separate page flags for the head and the tail of a compound page allows
the compiler to use bitops instead of operations on a word to check for a tail
page.  That is f.e.  important for virt_to_head_page() which is used in
various critical code paths (kfree for example):

Code for PageTail(page)

Before:

 mov    (%rdi),%rdx		page->flags
 mov    %rdx,%rax		3 bytes
 and    $0x12000,%eax		5 bytes
 cmp    $0x12000,%rax		6 bytes
 je     897 <kfree+0xa7>

After:

 mov    (%rdi),%rax
 test   $0x40,%ah			(3 bytes)
 jne    887 <kfree+0x97>

So we go from 14 bytes to 3 bytes and from 3 instructions to one.  From the
use of 2 registers we go to none.

We can only use page flags for this if we have page flags available.  This
patch introduces CONFIG_PAGEFLAGS_EXTENDED that is set if pageflags are not
scarce due to SPARSEMEM using page flags for its sectionid on 32 bit NUMA
platforms.

Additional page flag definitions can be added to the CONFIG_PAGEFLAGS_EXTENDED
section in page-flags.h if the functionality depends on PAGEFLAGS_EXTENDED or
if more page flag overlapping tricks are used for the !PAGEFLAGS_EXTENDED
fallback (the upcoming virtual compound patch may hook in here and Rik's/Lee's
additional page flags to solve the reclaim issues could also be added there
[hint...  hint...  where are these patchsets?]).

Avoiding the overlaying of Pg_reclaim also clears the way for possible use of
compound pages for the pagecache or on the LRU.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:22 -07:00
Christoph Lameter 0a128b2b1a pageflags: eliminate PG_xxx aliases
Remove aliases of PG_xxx.  We can easily drop those now and alias by
specifying the PG_xxx flag in the macro that generates the functions.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:22 -07:00
Christoph Lameter 2301696932 vmallocinfo: add caller information
Add caller information so that /proc/vmallocinfo shows where the allocation
request for a slice of vmalloc memory originated.

Results in output like this:

0xffffc20000000000-0xffffc20000801000 8392704 alloc_large_system_hash+0x127/0x246 pages=2048 vmalloc vpages
0xffffc20000801000-0xffffc20000806000   20480 alloc_large_system_hash+0x127/0x246 pages=4 vmalloc
0xffffc20000806000-0xffffc20000c07000 4198400 alloc_large_system_hash+0x127/0x246 pages=1024 vmalloc vpages
0xffffc20000c07000-0xffffc20000c0a000   12288 alloc_large_system_hash+0x127/0x246 pages=2 vmalloc
0xffffc20000c0a000-0xffffc20000c0c000    8192 acpi_os_map_memory+0x13/0x1c phys=cff68000 ioremap
0xffffc20000c0c000-0xffffc20000c0f000   12288 acpi_os_map_memory+0x13/0x1c phys=cff64000 ioremap
0xffffc20000c10000-0xffffc20000c15000   20480 acpi_os_map_memory+0x13/0x1c phys=cff65000 ioremap
0xffffc20000c16000-0xffffc20000c18000    8192 acpi_os_map_memory+0x13/0x1c phys=cff69000 ioremap
0xffffc20000c18000-0xffffc20000c1a000    8192 acpi_os_map_memory+0x13/0x1c phys=fed1f000 ioremap
0xffffc20000c1a000-0xffffc20000c1c000    8192 acpi_os_map_memory+0x13/0x1c phys=cff68000 ioremap
0xffffc20000c1c000-0xffffc20000c1e000    8192 acpi_os_map_memory+0x13/0x1c phys=cff68000 ioremap
0xffffc20000c1e000-0xffffc20000c20000    8192 acpi_os_map_memory+0x13/0x1c phys=cff68000 ioremap
0xffffc20000c20000-0xffffc20000c22000    8192 acpi_os_map_memory+0x13/0x1c phys=cff68000 ioremap
0xffffc20000c22000-0xffffc20000c24000    8192 acpi_os_map_memory+0x13/0x1c phys=cff68000 ioremap
0xffffc20000c24000-0xffffc20000c26000    8192 acpi_os_map_memory+0x13/0x1c phys=e0081000 ioremap
0xffffc20000c26000-0xffffc20000c28000    8192 acpi_os_map_memory+0x13/0x1c phys=e0080000 ioremap
0xffffc20000c28000-0xffffc20000c2d000   20480 alloc_large_system_hash+0x127/0x246 pages=4 vmalloc
0xffffc20000c2d000-0xffffc20000c31000   16384 tcp_init+0xd5/0x31c pages=3 vmalloc
0xffffc20000c31000-0xffffc20000c34000   12288 alloc_large_system_hash+0x127/0x246 pages=2 vmalloc
0xffffc20000c34000-0xffffc20000c36000    8192 init_vdso_vars+0xde/0x1f1
0xffffc20000c36000-0xffffc20000c38000    8192 pci_iomap+0x8a/0xb4 phys=d8e00000 ioremap
0xffffc20000c38000-0xffffc20000c3a000    8192 usb_hcd_pci_probe+0x139/0x295 [usbcore] phys=d8e00000 ioremap
0xffffc20000c3a000-0xffffc20000c3e000   16384 sys_swapon+0x509/0xa15 pages=3 vmalloc
0xffffc20000c40000-0xffffc20000c61000  135168 e1000_probe+0x1c4/0xa32 phys=d8a20000 ioremap
0xffffc20000c61000-0xffffc20000c6a000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
0xffffc20000c6a000-0xffffc20000c73000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
0xffffc20000c73000-0xffffc20000c7c000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
0xffffc20000c7c000-0xffffc20000c7f000   12288 e1000e_setup_tx_resources+0x29/0xbe pages=2 vmalloc
0xffffc20000c80000-0xffffc20001481000 8392704 pci_mmcfg_arch_init+0x90/0x118 phys=e0000000 ioremap
0xffffc20001481000-0xffffc20001682000 2101248 alloc_large_system_hash+0x127/0x246 pages=512 vmalloc
0xffffc20001682000-0xffffc20001e83000 8392704 alloc_large_system_hash+0x127/0x246 pages=2048 vmalloc vpages
0xffffc20001e83000-0xffffc20002204000 3674112 alloc_large_system_hash+0x127/0x246 pages=896 vmalloc vpages
0xffffc20002204000-0xffffc2000220d000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
0xffffc2000220d000-0xffffc20002216000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
0xffffc20002216000-0xffffc2000221f000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
0xffffc2000221f000-0xffffc20002228000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
0xffffc20002228000-0xffffc20002231000   36864 _xfs_buf_map_pages+0x8e/0xc0 vmap
0xffffc20002231000-0xffffc20002234000   12288 e1000e_setup_rx_resources+0x35/0x122 pages=2 vmalloc
0xffffc20002240000-0xffffc20002261000  135168 e1000_probe+0x1c4/0xa32 phys=d8a60000 ioremap
0xffffc20002261000-0xffffc2000270c000 4894720 sys_swapon+0x509/0xa15 pages=1194 vmalloc vpages
0xffffffffa0000000-0xffffffffa0022000  139264 module_alloc+0x4f/0x55 pages=33 vmalloc
0xffffffffa0022000-0xffffffffa0029000   28672 module_alloc+0x4f/0x55 pages=6 vmalloc
0xffffffffa002b000-0xffffffffa0034000   36864 module_alloc+0x4f/0x55 pages=8 vmalloc
0xffffffffa0034000-0xffffffffa003d000   36864 module_alloc+0x4f/0x55 pages=8 vmalloc
0xffffffffa003d000-0xffffffffa0049000   49152 module_alloc+0x4f/0x55 pages=11 vmalloc
0xffffffffa0049000-0xffffffffa0050000   28672 module_alloc+0x4f/0x55 pages=6 vmalloc

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:21 -07:00
Christoph Lameter a10aa57987 vmalloc: show vmalloced areas via /proc/vmallocinfo
Implement a new proc file that allows the display of the currently allocated
vmalloc memory.

It allows to see the users of vmalloc.  That is important if vmalloc space is
scarce (i386 for example).

And it's going to be important for the compound page fallback to vmalloc.
Many of the current users can be switched to use compound pages with fallback.
 This means that the number of users of vmalloc is reduced and page tables no
longer necessary to access the memory.  /proc/vmallocinfo allows to review how
that reduction occurs.

If memory becomes fragmented and larger order allocations are no longer
possible then /proc/vmallocinfo allows to see which compound page allocations
fell back to virtual compound pages.  That is important for new users of
virtual compound pages.  Such as order 1 stack allocation etc that may
fallback to virtual compound pages in the future.

/proc/vmallocinfo permissions are made readable-only-by-root to avoid possible
information leakage.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: CONFIG_MMU=n build fix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:21 -07:00
Miklos Szeredi ac6aadb24b mm: rotate_reclaimable_page() cleanup
Clean up messy conditional calling of test_clear_page_writeback() from both
rotate_reclaimable_page() and end_page_writeback().

The only user of rotate_reclaimable_page() is end_page_writeback() so this is
OK.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:20 -07:00
S.Caglar Onur f05111f501 mm/page_alloc.c: fix indentation
zlc_setup(): handle jiffies wraparound
(10ed273f50) changes tab with spaces

Signed-off-by: S.Caglar Onur <caglar@pardus.org.tr>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:20 -07:00
Andi Kleen b5ee5befa7 dmapool: enable debugging for CONFIG_SLUB_DEBUG_ON too
Previously it was only enabled for CONFIG_DEBUG_SLAB.

Not hooked into the slub runtime debug configuration, so you currently only
get it with CONFIG_SLUB_DEBUG_ON, not plain CONFIG_SLUB_DEBUG

Acked-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:20 -07:00
Lee Schermerhorn a43361cf3c mempolicy: fix parsing of tmpfs mpol mount option
Parsing of new mode flags in the tmpfs mpol mount option is slightly broken:

Setting a valid flag works OK:
	#mount -o remount,mpol=bind=static:1-2 /dev/shm
	#mount
	...
	tmpfs on /dev/shm type tmpfs (rw,mpol=bind=static:1-2)
	...

However, we can't remove them or change them, once we've
set a valid flag:

	#mount -o remount,mpol=bind:1-2 /dev/shm
	#mount
	...
	tmpfs on /dev/shm type tmpfs (rw,mpol=bind:1-2)
	...

It SAYS it removed it, but that's just a copy of the input
string.  If we now try to set it to a different flag, we
get:

	#mount -o remount,mpol=bind=relative:1-2 /dev/shm
	mount: /dev/shm not mounted already, or bad option

And on the console, we see:
	tmpfs: Bad value 'bind' for mount option 'mpol'
	                      ^ lost remainder of string

Furthermore, bogus flags are accepted with out error.
Granted, they are a no-op:

	#mount -o remount,mpol=interleave=foo:0-3 /dev/shm
	#mount
	...
	tmpfs on /dev/shm type tmpfs (rw,mpol=interleave=foo:0-3)

Again, that's just a copy of the input string shown by the mount command.

This patch fixes the behavior by pre-zeroing the flags so that only one of the
mutually exclusive flags can be set at one time.  It also reports an error
when an unrecognized flag is specified.

The check for both flags being set is removed because it can't happen with
this implementation.  If we ever want to support multiple non-exclusive flags,
this area will need rework and we will need to check that any mutually
exclusive flags aren't specified.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Eric Whitney <eric.whitney@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:20 -07:00