Commit Graph

1940 Commits

Author SHA1 Message Date
Nishanth Aravamudan 064d9efe94 hugetlb: fix overcommit locking
proc_doulongvec_minmax() calls copy_to_user()/copy_from_user(), so we can't
hold hugetlb_lock over the call.  Use a dummy variable to store the sysctl
result, like in hugetlb_sysctl_handler(), then grab the lock to update
nr_overcommit_huge_pages.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Reported-by: Miles Lane <miles.lane@gmail.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-13 16:21:18 -08:00
Harvey Harrison b5606c2d44 remove final fastcall users
fastcall always expands to empty, remove it.

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>
2008-02-13 16:21:18 -08:00
KOSAKI Motohiro 31f1de46b9 mempolicy: silently restrict nodemask to allowed nodes
Kosaki Motohito noted that "numactl --interleave=all ..." failed in the
presence of memoryless nodes.  This patch attempts to fix that problem.

Some background:

numactl --interleave=all calls set_mempolicy(2) with a fully populated
[out to MAXNUMNODES] nodemask.  set_mempolicy() [in do_set_mempolicy()]
calls contextualize_policy() which requires that the nodemask be a
subset of the current task's mems_allowed; else EINVAL will be returned.

A task's mems_allowed will always be a subset of node_states[N_HIGH_MEMORY]
i.e., nodes with memory.  So, a fully populated nodemask will be
declared invalid if it includes memoryless nodes.

  NOTE:  the same thing will occur when running in a cpuset
         with restricted mem_allowed--for the same reason:
         node mask contains dis-allowed nodes.

mbind(2), on the other hand, just masks off any nodes in the nodemask
that are not included in the caller's mems_allowed.

In each case [mbind() and set_mempolicy()], mpol_check_policy() will
complain [again, resulting in EINVAL] if the nodemask contains any
memoryless nodes.  This is somewhat redundant as mpol_new() will remove
memoryless nodes for interleave policy, as will bind_zonelist()--called
by mpol_new() for BIND policy.

Proposed fix:

1) modify contextualize_policy logic to:
   a) remember whether the incoming node mask is empty.
   b) if not, restrict the nodemask to allowed nodes, as is
      currently done in-line for mbind().  This guarantees
      that the resulting mask includes only nodes with memory.

      NOTE:  this is a [benign, IMO] change in behavior for
             set_mempolicy().  Dis-allowed nodes will be
             silently ignored, rather than returning an error.

   c) fold this code into mpol_check_policy(), replace 2 calls to
      contextualize_policy() to call mpol_check_policy() directly
      and remove contextualize_policy().

2) In existing mpol_check_policy() logic, after "contextualization":
   a) MPOL_DEFAULT:  require that in coming mask "was_empty"
   b) MPOL_{BIND|INTERLEAVE}:  require that contextualized nodemask
      contains at least one node.
   c) add a case for MPOL_PREFERRED:  if in coming was not empty
      and resulting mask IS empty, user specified invalid nodes.
      Return EINVAL.
   c) remove the now redundant check for memoryless nodes

3) remove the now redundant masking of policy nodes for interleave
   policy from mpol_new().

4) Now that mpol_check_policy() contextualizes the nodemask, remove
   the in-line nodes_and() from sys_mbind().  I believe that this
   restores mbind() to the behavior before the memoryless-nodes
   patch series.  E.g., we'll no longer treat an invalid nodemask
   with MPOL_PREFERRED as local allocation.

[ Patch history:

  v1 -> v2:
   - Communicate whether or not incoming node mask was empty to
     mpol_check_policy() for better error checking.
   - As suggested by David Rientjes, remove the now unused
     cpuset_nodes_subset_current_mems_allowed() from cpuset.h

  v2 -> v3:
   - As suggested by Kosaki Motohito, fold the "contextualization"
     of policy nodemask into mpol_check_policy().  Looks a little
     cleaner. ]

Signed-off-by:  Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by:  KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Tested-by:      KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by:       David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-11 20:48:29 -08:00
Jonathan Corbet 900cf086fd Be more robust about bad arguments in get_user_pages()
So I spent a while pounding my head against my monitor trying to figure
out the vmsplice() vulnerability - how could a failure to check for
*read* access turn into a root exploit? It turns out that it's a buffer
overflow problem which is made easy by the way get_user_pages() is
coded.

In particular, "len" is a signed int, and it is only checked at the
*end* of a do {} while() loop.  So, if it is passed in as zero, the loop
will execute once and decrement len to -1.  At that point, the loop will
proceed until the next invalid address is found; in the process, it will
likely overflow the pages array passed in to get_user_pages().

I think that, if get_user_pages() has been asked to grab zero pages,
that's what it should do.  Thus this patch; it is, among other things,
enough to block the (already fixed) root exploit and any others which
might be lurking in similar code.  I also think that the number of pages
should be unsigned, but changing the prototype of this function probably
requires some more careful review.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-11 20:44:44 -08:00
David Rientjes 60c12b1202 memcontrol: add vm_match_cgroup()
mm_cgroup() is exclusively used to test whether an mm's mem_cgroup pointer
is pointing to a specific cgroup.  Instead of returning the pointer, we can
just do the test itself in a new macro:

	vm_match_cgroup(mm, cgroup)

returns non-zero if the mm's mem_cgroup points to cgroup.  Otherwise it
returns zero.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-09 11:08:33 -08:00
Nick Piggin b1d0e4f535 mm: special mapping nopage
Convert special mapping install from nopage to fault.

Because the "vm_file" is NULL for the special mapping, the generic VM
code has messed up "vm_pgoff" thinking that it's an anonymous mapping
and the offset does't matter.  For that reason, we need to undo the
vm_pgoff offset that got added into vmf->pgoff.

[ We _really_ should clean that up - either by making this whole special
  mapping code just use a real file entry rather than that ugly array of
  "struct page" pointers, or by just making the VM code realize that
  even if vm_file is NULL it may not be a regular anonymous mmap.
							 - Linus ]

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 18:57:39 -08:00
Martin Schwidefsky 2f569afd9c CONFIG_HIGHPTE vs. sub-page page tables.
Background: I've implemented 1K/2K page tables for s390.  These sub-page
page tables are required to properly support the s390 virtualization
instruction with KVM.  The SIE instruction requires that the page tables
have 256 page table entries (pte) followed by 256 page status table entries
(pgste).  The pgstes are only required if the process is using the SIE
instruction.  The pgstes are updated by the hardware and by the hypervisor
for a number of reasons, one of them is dirty and reference bit tracking.
To avoid wasting memory the standard pte table allocation should return
1K/2K (31/64 bit) and 2K/4K if the process is using SIE.

Problem: Page size on s390 is 4K, page table size is 1K or 2K.  That means
the s390 version for pte_alloc_one cannot return a pointer to a struct
page.  Trouble is that with the CONFIG_HIGHPTE feature on x86 pte_alloc_one
cannot return a pointer to a pte either, since that would require more than
32 bit for the return value of pte_alloc_one (and the pte * would not be
accessible since its not kmapped).

Solution: The only solution I found to this dilemma is a new typedef: a
pgtable_t.  For s390 pgtable_t will be a (pte *) - to be introduced with a
later patch.  For everybody else it will be a (struct page *).  The
additional problem with the initialization of the ptl lock and the
NR_PAGETABLE accounting is solved with a constructor pgtable_page_ctor and
a destructor pgtable_page_dtor.  The page table allocation and free
functions need to call these two whenever a page table page is allocated or
freed.  pmd_populate will get a pgtable_t instead of a struct page pointer.
 To get the pgtable_t back from a pmd entry that has been installed with
pmd_populate a new function pmd_pgtable is added.  It replaces the pmd_page
call in free_pte_range and apply_to_pte_range.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:42 -08:00
Andrew Morton b76db73540 mount-options-fix-tmpfs-fix
Documentation/SubmitCheckist, please.

Cc: Hugh Dickins <hugh@veritas.com>
Cc: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:41 -08:00
akpm@linux-foundation.org 680d794bab mount options: fix tmpfs
Add .show_options super operation to tmpfs.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
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>
2008-02-08 09:22:41 -08:00
Christoph Hellwig 36e7891442 kill do_generic_mapping_read
do_generic_mapping_read was used by gfs2 for internals reads, but this use
of the interface was rather suboptimal (as was the whole interface) and has
been replaced by an internal helper now.  This patch kills
do_generic_mapping_read and surrounding damage in preparation of additional
cleanups for the buffered read path.

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>
2008-02-08 09:22:39 -08:00
Jan Kara 2004dc8eec Use pgoff_t instead of unsigned long
Convert variables containing page indexes to pgoff_t.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:32 -08:00
Harvey Harrison edde08f2a8 misc: removal of final callers using fastcall
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>
2008-02-08 09:22:31 -08:00
Nishanth Aravamudan a3d0c6aa1b hugetlb: add locking for overcommit sysctl
When I replaced hugetlb_dynamic_pool with nr_overcommit_hugepages I used
proc_doulongvec_minmax() directly.  However, hugetlb.c's locking rules
require that all counter modifications occur under the hugetlb_lock.  Add a
callback into the hugetlb code similar to the one for nr_hugepages.  Grab
the lock around the manipulation of nr_overcommit_hugepages in
proc_doulongvec_minmax().

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Acked-by: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:23 -08:00
Ingo Molnar 3adbefee6f SLUB: fix checkpatch warnings
fix checkpatch --file mm/slub.c errors and warnings.

 $ q-code-quality-compare
                                      errors   lines of code   errors/KLOC
 mm/slub.c      [before]                  22            4204           5.2
 mm/slub.c      [after]                    0            4210             0

no code changed:

    text    data     bss     dec     hex filename
   22195    8634     136   30965    78f5 slub.o.before
   22195    8634     136   30965    78f5 slub.o.after

   md5:
     93cdfbec2d6450622163c590e1064358  slub.o.before.asm
     93cdfbec2d6450622163c590e1064358  slub.o.after.asm

[clameter: rediffed against Pekka's cleanup patch, omitted
moves of the name of a function to the start of line]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
2008-02-07 17:52:39 -08:00
Nick Piggin a76d354629 Use non atomic unlock
Slub can use the non-atomic version to unlock because other flags will not
get modified with the lock held.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2008-02-07 17:47:42 -08:00
Christoph Lameter 8ff12cfc00 SLUB: Support for performance statistics
The statistics provided here allow the monitoring of allocator behavior but
at the cost of some (minimal) loss of performance. Counters are placed in
SLUB's per cpu data structure. The per cpu structure may be extended by the
statistics to grow larger than one cacheline which will increase the cache
footprint of SLUB.

There is a compile option to enable/disable the inclusion of the runtime
statistics and its off by default.

The slabinfo tool is enhanced to support these statistics via two options:

-D 	Switches the line of information displayed for a slab from size
	mode to activity mode.

-A	Sorts the slabs displayed by activity. This allows the display of
	the slabs most important to the performance of a certain load.

-r	Report option will report detailed statistics on

Example (tbench load):

slabinfo -AD		->Shows the most active slabs

Name                   Objects    Alloc     Free   %Fast
skbuff_fclone_cache         33 111953835 111953835  99  99
:0000192                  2666  5283688  5281047  99  99
:0001024                   849  5247230  5246389  83  83
vm_area_struct            1349   119642   118355  91  22
:0004096                    15    66753    66751  98  98
:0000064                  2067    25297    23383  98  78
dentry                   10259    28635    18464  91  45
:0000080                 11004    18950     8089  98  98
:0000096                  1703    12358    10784  99  98
:0000128                   762    10582     9875  94  18
:0000512                   184     9807     9647  95  81
:0002048                   479     9669     9195  83  65
anon_vma                   777     9461     9002  99  71
kmalloc-8                 6492     9981     5624  99  97
:0000768                   258     7174     6931  58  15

So the skbuff_fclone_cache is of highest importance for the tbench load.
Pretty high load on the 192 sized slab. Look for the aliases

slabinfo -a | grep 000192
:0000192     <- xfs_btree_cur filp kmalloc-192 uid_cache tw_sock_TCP
	request_sock_TCPv6 tw_sock_TCPv6 skbuff_head_cache xfs_ili

Likely skbuff_head_cache.


Looking into the statistics of the skbuff_fclone_cache is possible through

slabinfo skbuff_fclone_cache	->-r option implied if cache name is mentioned


.... Usual output ...

Slab Perf Counter       Alloc     Free %Al %Fr
--------------------------------------------------
Fastpath             111953360 111946981  99  99
Slowpath                 1044     7423   0   0
Page Alloc                272      264   0   0
Add partial                25      325   0   0
Remove partial             86      264   0   0
RemoteObj/SlabFrozen      350     4832   0   0
Total                111954404 111954404

Flushes       49 Refill        0
Deactivate Full=325(92%) Empty=0(0%) ToHead=24(6%) ToTail=1(0%)

Looks good because the fastpath is overwhelmingly taken.


skbuff_head_cache:

Slab Perf Counter       Alloc     Free %Al %Fr
--------------------------------------------------
Fastpath              5297262  5259882  99  99
Slowpath                 4477    39586   0   0
Page Alloc                937      824   0   0
Add partial                 0     2515   0   0
Remove partial           1691      824   0   0
RemoteObj/SlabFrozen     2621     9684   0   0
Total                 5301739  5299468

Deactivate Full=2620(100%) Empty=0(0%) ToHead=0(0%) ToTail=0(0%)


Descriptions of the output:

Total:		The total number of allocation and frees that occurred for a
		slab

Fastpath:	The number of allocations/frees that used the fastpath.

Slowpath:	Other allocations

Page Alloc:	Number of calls to the page allocator as a result of slowpath
		processing

Add Partial:	Number of slabs added to the partial list through free or
		alloc (occurs during cpuslab flushes)

Remove Partial:	Number of slabs removed from the partial list as a result of
		allocations retrieving a partial slab or by a free freeing
		the last object of a slab.

RemoteObj/Froz:	How many times were remotely freed object encountered when a
		slab was about to be deactivated. Frozen: How many times was
		free able to skip list processing because the slab was in use
		as the cpuslab of another processor.

Flushes:	Number of times the cpuslab was flushed on request
		(kmem_cache_shrink, may result from races in __slab_alloc)

Refill:		Number of times we were able to refill the cpuslab from
		remotely freed objects for the same slab.

Deactivate:	Statistics how slabs were deactivated. Shows how they were
		put onto the partial list.

In general fastpath is very good. Slowpath without partial list processing is
also desirable. Any touching of partial list uses node specific locks which
may potentially cause list lock contention.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
2008-02-07 17:47:41 -08:00
Christoph Lameter 1f84260c8c SLUB: Alternate fast paths using cmpxchg_local
Provide an alternate implementation of the SLUB fast paths for alloc
and free using cmpxchg_local. The cmpxchg_local fast path is selected
for arches that have CONFIG_FAST_CMPXCHG_LOCAL set. An arch should only
set CONFIG_FAST_CMPXCHG_LOCAL if the cmpxchg_local is faster than an
interrupt enable/disable sequence. This is known to be true for both
x86 platforms so set FAST_CMPXCHG_LOCAL for both arches.

Currently another requirement for the fastpath is that the kernel is
compiled without preemption. The restriction will go away with the
introduction of a new per cpu allocator and new per cpu operations.

The advantages of a cmpxchg_local based fast path are:

1. Potentially lower cycle count (30%-60% faster)

2. There is no need to disable and enable interrupts on the fast path.
   Currently interrupts have to be disabled and enabled on every
   slab operation. This is likely avoiding a significant percentage
   of interrupt off / on sequences in the kernel.

3. The disposal of freed slabs can occur with interrupts enabled.

The alternate path is realized using #ifdef's. Several attempts to do the
same with macros and inline functions resulted in a mess (in particular due
to the strange way that local_interrupt_save() handles its argument and due
to the need to define macros/functions that sometimes disable interrupts
and sometimes do something else).

[clameter: Stripped preempt bits and disabled fastpath if preempt is enabled]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2008-02-07 17:47:41 -08:00
Christoph Lameter 683d0baad3 SLUB: Use unique end pointer for each slab page.
We use a NULL pointer on freelists to signal that there are no more objects.
However the NULL pointers of all slabs match in contrast to the pointers to
the real objects which are in different ranges for different slab pages.

Change the end pointer to be a pointer to the first object and set bit 0.
Every slab will then have a different end pointer. This is necessary to ensure
that end markers can be matched to the source slab during cmpxchg_local.

Bring back the use of the mapping field by SLUB since we would otherwise have
to call a relatively expensive function page_address() in __slab_alloc().  Use
of the mapping field allows avoiding a call to page_address() in various other
functions as well.

There is no need to change the page_mapping() function since bit 0 is set on
the mapping as also for anonymous pages.  page_mapping(slab_page) will
therefore still return NULL although the mapping field is overloaded.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2008-02-07 17:47:41 -08:00
Christoph Lameter 5bb983b0cc SLUB: Deal with annoying gcc warning on kfree()
gcc 4.2 spits out an annoying warning if one casts a const void *
pointer to a void * pointer. No warning is generated if the
conversion is done through an assignment.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
2008-02-07 17:47:41 -08:00
Bernhard Walle 72a7fe3967 Introduce flags for reserve_bootmem()
This patchset adds a flags variable to reserve_bootmem() and uses the
BOOTMEM_EXCLUSIVE flag in crashkernel reservation code to detect collisions
between crashkernel area and already used memory.

This patch:

Change the reserve_bootmem() function to accept a new flag BOOTMEM_EXCLUSIVE.
If that flag is set, the function returns with -EBUSY if the memory already
has been reserved in the past.  This is to avoid conflicts.

Because that code runs before SMP initialisation, there's no race condition
inside reserve_bootmem_core().

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix powerpc build]
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: <linux-arch@vger.kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:25 -08:00
Balbir Singh 3c541e14bf Memory controller remove control_type feature
Based on the discussion at http://lkml.org/lkml/2007/12/20/383, it was felt
that control_type might not be a good thing to implement right away.  We
can add this flexibility at a later point when required.

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-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>
2008-02-07 08:42:22 -08:00
KAMEZAWA Hiroyuki 072c56c13e per-zone and reclaim enhancements for memory controller: per-zone-lock for cgroup
Now, lru is per-zone.

Then, lru_lock can be (should be) per-zone, too.
This patch implementes per-zone lru lock.

lru_lock is placed into mem_cgroup_per_zone struct.

lock can be accessed by
   mz = mem_cgroup_zoneinfo(mem_cgroup, node, zone);
   &mz->lru_lock

   or
   mz = page_cgroup_zoneinfo(page_cgroup);
   &mz->lru_lock

Signed-off-by: KAMEZAWA hiroyuki <kmaezawa.hiroyu@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:22 -08:00
KAMEZAWA Hiroyuki 1ecaab2bd2 per-zone and reclaim enhancements for memory controller: per zone lru for cgroup
This patch implements per-zone lru for memory cgroup.
This patch makes use of mem_cgroup_per_zone struct for per zone lru.

LRU can be accessed by

   mz = mem_cgroup_zoneinfo(mem_cgroup, node, zone);
   &mz->active_list
   &mz->inactive_list

   or
   mz = page_cgroup_zoneinfo(page_cgroup);
   &mz->active_list
   &mz->inactive_list

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:22 -08:00
KAMEZAWA Hiroyuki 1cfb419b39 per-zone and reclaim enhancements for memory controller: modifies vmscan.c for isolate globa/cgroup lru activity
When using memory controller, there are 2 levels of memory reclaim.
 1. zone memory reclaim because of system/zone memory shortage.
 2. memory cgroup memory reclaim because of hitting limit.

These two can be distinguished by sc->mem_cgroup parameter.
(scan_global_lru() macro)

This patch tries to make memory cgroup reclaim routine avoid affecting
system/zone memory reclaim. This patch inserts if (scan_global_lru()) and
hook to memory_cgroup reclaim support functions.

This patch can be a help for isolating system lru activity and group lru
activity and shows what additional functions are necessary.

 * mem_cgroup_calc_mapped_ratio() ... calculate mapped ratio for cgroup.
 * mem_cgroup_reclaim_imbalance() ... calculate active/inactive balance in
                                        cgroup.
 * mem_cgroup_calc_reclaim_active() ... calculate the number of active pages to
                                be scanned in this priority in mem_cgroup.

 * mem_cgroup_calc_reclaim_inactive() ... calculate the number of inactive pages
                                to be scanned in this priority in mem_cgroup.

 * mem_cgroup_all_unreclaimable() .. checks cgroup's page is all unreclaimable
                                     or not.
 * mem_cgroup_get_reclaim_priority() ...
 * mem_cgroup_note_reclaim_priority() ... record reclaim priority (temporal)
 * mem_cgroup_remember_reclaim_priority()
                             .... record reclaim priority as
                                  zone->prev_priority.
                                  This value is used for calc reclaim_mapped.

[akpm@linux-foundation.org: fix unused var warning]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:22 -08:00
KAMEZAWA Hiroyuki cc38108e1b per-zone and reclaim enhancements for memory controller: calculate the number of pages to be scanned per cgroup
Define function for calculating the number of scan target on each Zone/LRU.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:22 -08:00
KAMEZAWA Hiroyuki 6c48a1d040 per-zone and reclaim enhancements for memory controller: remember reclaim priority in memory cgroup
Functions to remember reclaim priority per cgroup (as zone->prev_priority)

[akpm@linux-foundation.org: build fixes]
[akpm@linux-foundation.org: more build fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:22 -08:00
KAMEZAWA Hiroyuki 5932f3671b per-zone and reclaim enhancements for memory controller: calculate active/inactive imbalance per cgroup
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:21 -08:00
KAMEZAWA Hiroyuki 58ae83db2a per-zone and reclaim enhancements for memory controller: calculate mapper_ratio per cgroup
Define function for calculating mapped_ratio in memory cgroup.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:21 -08:00
KAMEZAWA Hiroyuki 6d12e2d8dd per-zone and reclaim enhancements for memory controller: per-zone active inactive counter
This patch adds per-zone status in memory cgroup.  These values are often read
(as per-zone value) by page reclaiming.

In current design, per-zone stat is just a unsigned long value and not an
atomic value because they are modified only under lru_lock.  (So, atomic_ops
is not necessary.)

This patch adds ACTIVE and INACTIVE per-zone status values.

For handling per-zone status, this patch adds
  struct mem_cgroup_per_zone {
		...
  }
and some helper functions. This will be useful to add per-zone objects
in mem_cgroup.

This patch turns memory controller's early_init to be 0 for calling
kmalloc() in initialization.

Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:21 -08:00
KAMEZAWA Hiroyuki c0149530d0 per-zone and reclaim enhancements for memory controller: nid/zid helper function for cgroup
Add macro to get node_id and zone_id of page_cgroup.  Will be used in
per-zone-xxx patches and others.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:21 -08:00
KAMEZAWA Hiroyuki 91a45470f7 per-zone and reclaim enhancements for memory controller: add scan_global_lru macro
This is used to detect which scan_control scans global lru or mem_cgroup lru.
And compiled to be static value (1) when memory controller is not configured.
This may make the meaning obvious.

Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:21 -08:00
KAMEZAWA Hiroyuki df878fb04d memory cgroup enhancements: implicit force_empty() at rmdir
Add pre_destroy handler for mem_cgroup and try to make mem_cgroup empty at
rmdir().

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:20 -08:00
KAMEZAWA Hiroyuki d2ceb9b7dd memory cgroup enhancements: add memory.stat file
Show accounted information of memory cgroup by memory.stat file

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix printk warning]
Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: David Rientjes <rientjes@google.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:20 -08:00
KAMEZAWA Hiroyuki d52aa412d4 memory cgroup enhancements: add status accounting function for memory cgroup
Add statistics account infrastructure for memory controller.  All account
information is stored per-cpu and caller will not have to take lock or use
atomic ops.  This will be used by memory.stat file later.

CACHE includes swapcache now. I'd like to divide it to
PAGECACHE and SWAPCACHE later.

This patch adds 3 functions for accounting.
 * __mem_cgroup_stat_add() ... for usual routine.
 * __mem_cgroup_stat_add_safe ... for calling under irq_disabled section.
 * mem_cgroup_read_stat() ... for reading stat value.
 * renamed PAGECACHE to CACHE (because it may include swapcache *now*)

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix smp_processor_id-in-preemptible]
[akpm@linux-foundation.org: uninline things]
[akpm@linux-foundation.org: remove dead code]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: David Rientjes <rientjes@google.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.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>
2008-02-07 08:42:20 -08:00
KAMEZAWA Hiroyuki 3564c7c451 memory cgroup enhancements: remember "a page is on active list of cgroup or not"
Remember page_cgroup is on active_list or not in page_cgroup->flags.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: David Rientjes <rientjes@google.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:20 -08:00
Hugh Dickins 82369553d6 memcgroup: fix hang with shmem/tmpfs
The memcgroup regime relies upon a cgroup reclaiming pages from itself within
add_to_page_cache: which may involve some waiting.  Whereas shmem and tmpfs
rely upon using add_to_page_cache while holding a spinlock: when it cannot
wait.  The consequence is that when a cgroup reaches its limit, shmem_getpage
just hangs - unless there is outside memory pressure too, neither kswapd nor
radix_tree_preload get it out of the retry loop.

In most cases we can mem_cgroup_cache_charge the page waitably first, to
attach the page_cgroup in advance, so add_to_page_cache will do no more than
increment a count; then mem_cgroup_uncharge_page after (in both success and
failure cases) to balance the books again.

And where there used to be a congestion_wait for kswapd (recently made
redundant by radix_tree_preload), use mem_cgroup_cache_charge with NULL page
to go through a cycle of allocation and freeing, without accounting to any
particular page, and without updating the statistics vector.  This brings the
cgroup below its limit so the next try usually succeeds.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
2008-02-07 08:42:20 -08:00
Hugh Dickins 3be91277e7 memcgroup: tidy up mem_cgroup_charge_common
Tidy up mem_cgroup_charge_common before extending it.  Adjust some comments,
but mainly clean up its loop: I've an aversion to loops full of continues,
then a break or a goto at the bottom.  And the is_atomic test should be on the
__GFP_WAIT bit, not GFP_ATOMIC bits.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
2008-02-07 08:42:20 -08:00
Balbir Singh ac44d354d5 Memory controller use rcu_read_lock() in mem_cgroup_cache_charge()
Hugh Dickins noticed that we were using rcu_dereference() without
rcu_read_lock() in the cache charging routine. The patch below fixes
this problem

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>
2008-02-07 08:42:20 -08:00
KAMEZAWA Hiroyuki 217bc3194d memory cgroup enhancements: remember "a page is charged as page cache"
Add a flag to page_cgroup to remember "this page is
charged as cache."
cache here includes page caches and swap cache.
This is useful for implementing precise accounting in memory cgroup.
TODO:
  distinguish page-cache and swap-cache

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: David Rientjes <rientjes@google.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:20 -08:00
KAMEZAWA Hiroyuki cc8475822f memory cgroup enhancements: force_empty interface for dropping all account in empty cgroup
This patch adds an interface "memory.force_empty".  Any write to this file
will drop all charges in this cgroup if there is no task under.

%echo 1 > /....../memory.force_empty

will drop all charges of memory cgroup if cgroup's tasks is empty.

This is useful to invoke rmdir() against memory cgroup successfully.

Tested and worked well on x86_64/fake-NUMA system.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: David Rientjes <rientjes@google.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:20 -08:00
KAMEZAWA Hiroyuki 417eead304 memory cgroup enhancements: fix zone handling in try_to_free_mem_cgroup_page
Because NODE_DATA(node)->node_zonelists[] is guaranteed to contain all
necessary zones, it is not necessary to use for_each_online_node.

And this for_each_online_node() makes reclaim routine start always
from node 0. This is not good. This patch makes reclaim start from
caller's node and just use usual (default) zonelist order.

[akpm@linux-foundation.org: fix warning]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: David Rientjes <rientjes@google.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:20 -08:00
Hugh Dickins fa1de9008c memcgroup: revert swap_state mods
If we're charging rss and we're charging cache, it seems obvious that we
should be charging swapcache - as has been done.  But in practice that
doesn't work out so well: both swapin readahead and swapoff leave the
majority of pages charged to the wrong cgroup (the cgroup that happened to
read them in, rather than the cgroup to which they belong).

(Which is why unuse_pte's GFP_KERNEL while holding pte lock never showed up
as a problem: no allocation was ever done there, every page read being
already charged to the cgroup which initiated the swapoff.)

It all works rather better if we leave the charging to do_swap_page and
unuse_pte, and do nothing for swapcache itself: revert mm/swap_state.c to
what it was before the memory-controller patches.  This also speeds up
significantly a contained process working at its limit: because it no
longer needs to keep waiting for swap writeback to complete.

Is it unfair that swap pages become uncharged once they're unmapped, even
though they're still clearly private to particular cgroups?  For a short
while, yes; but PageReclaim arranges for those pages to go to the end of
the inactive list and be reclaimed soon if necessary.

shmem/tmpfs pages are a distinct case: their charging also benefits from
this change, but their second life on the lists as swapcache pages may
prove more unfair - that I need to check next.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: David Rientjes <rientjes@google.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:20 -08:00
Hugh Dickins 436c6541b1 memcgroup: fix zone isolation OOM
mem_cgroup_charge_common shows a tendency to OOM without good reason, when
a memhog goes well beyond its rss limit but with plenty of swap available.
Seen on x86 but not on PowerPC; seen when the next patch omits swapcache
from memcgroup, but we presume it can happen without.

mem_cgroup_isolate_pages is not quite satisfying reclaim's criteria for OOM
avoidance.  Already it has to scan beyond the nr_to_scan limit when it
finds a !LRU page or an active page when handling inactive or an inactive
page when handling active.  It needs to do exactly the same when it finds a
page from the wrong zone (the x86 tests had two zones, the PowerPC tests
had only one).

Don't increment scan and then decrement it in these cases, just move the
incrementation down.  Fix recent off-by-one when checking against
nr_to_scan.  Cut out "Check if the meta page went away from under us",
presumably left over from early debugging: no amount of such checks could
save us if this list really were being updated without locking.

This change does make the unlimited scan while holding two spinlocks
even worse - bad for latency and bad for containment; but that's a
separate issue which is better left to be fixed a little later.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: David Rientjes <rientjes@google.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:20 -08:00
KAMEZAWA Hiroyuki ff7283fa3a bugfix for memory cgroup controller: avoid !PageLRU page in mem_cgroup_isolate_pages
This patch makes mem_cgroup_isolate_pages() to be

  - ignore !PageLRU pages.
  - fixes the bug that isolation makes no progress if page_zone(page) != zone
    page once find. (just increment scan in this case.)

kswapd and memory migration removes a page from list when it handles
a page for reclaiming/migration.

Because __isolate_lru_page() doesn't moves page !PageLRU pages, it will
be safe to avoid touching !PageLRU() page and its page_cgroup.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: David Rientjes <rientjes@google.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:20 -08:00
KAMEZAWA Hiroyuki ae41be3742 bugfix for memory cgroup controller: migration under memory controller fix
While using memory control cgroup, page-migration under it works as following.
==
 1. uncharge all refs at try to unmap.
 2. charge regs again remove_migration_ptes()
==
This is simple but has following problems.
==
 The page is uncharged and charged back again if *mapped*.
    - This means that cgroup before migration can be different from one after
      migration
    - If page is not mapped but charged as page cache, charge is just ignored
      (because not mapped, it will not be uncharged before migration)
      This is memory leak.
==
This patch tries to keep memory cgroup at page migration by increasing
one refcnt during it. 3 functions are added.

 mem_cgroup_prepare_migration() --- increase refcnt of page->page_cgroup
 mem_cgroup_end_migration()     --- decrease refcnt of page->page_cgroup
 mem_cgroup_page_migration() --- copy page->page_cgroup from old page to
                                 new page.

During migration
  - old page is under PG_locked.
  - new page is under PG_locked, too.
  - both old page and new page is not on LRU.

These 3 facts guarantee that page_cgroup() migration has no race.

Tested and worked well in x86_64/fake-NUMA box.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: David Rientjes <rientjes@google.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:19 -08:00
KAMEZAWA Hiroyuki 9175e0311e bugfix for memory controller: add helper function for assigning cgroup to page
This patch adds following functions.
   - clear_page_cgroup(page, pc)
   - page_cgroup_assign_new_page_group(page, pc)

Mainly for cleanup.

A manner "check page->cgroup again after lock_page_cgroup()" is
implemented in straight way.

A comment in mem_cgroup_uncharge() will be removed by force-empty patch

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: David Rientjes <rientjes@google.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:19 -08:00
Rik van Riel f1a9ee758d kswapd should only wait on IO if there is IO
The current kswapd (and try_to_free_pages) code has an oddity where the
code will wait on IO, even if there is no IO in flight.  This problem is
notable especially when the system scans through many unfreeable pages,
causing unnecessary stalls in the VM.

Additionally, tasks without __GFP_FS or __GFP_IO in the direct reclaim path
will sleep if a significant number of pages are encountered that should be
written out.  This gives kswapd a chance to write out those pages, while
the direct reclaim task sleeps.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:19 -08:00
David Rientjes fef1bdd68c oom: add sysctl to enable task memory dump
Adds a new sysctl, 'oom_dump_tasks', that enables the kernel to produce a
dump of all system tasks (excluding kernel threads) when performing an
OOM-killing.  Information includes pid, uid, tgid, vm size, rss, cpu,
oom_adj score, and name.

This is helpful for determining why there was an OOM condition and which
rogue task caused it.

It is configurable so that large systems, such as those with several
thousand tasks, do not incur a performance penalty associated with dumping
data they may not desire.

If an OOM was triggered as a result of a memory controller, the tasklist
shall be filtered to exclude tasks that are not a member of the same
cgroup.

Cc: Andrea Arcangeli <andrea@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:19 -08:00
David Rientjes 4c4a221489 memcontrol: move oom task exclusion to tasklist scan
Creates a helper function to return non-zero if a task is a member of a
memory controller:

	int task_in_mem_cgroup(const struct task_struct *task,
			       const struct mem_cgroup *mem);

When the OOM killer is constrained by the memory controller, the exclusion
of tasks that are not a member of that controller was previously misplaced
and appeared in the badness scoring function.  It should be excluded
during the tasklist scan in select_bad_process() instead.

[akpm@linux-foundation.org: build fix]
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:19 -08:00
Badari Pulavarty 4c6bc8dd5a mem-controller gfp-mask fix
Need to strip __GFP_HIGHMEM flag while passing to mem_container_cache_charge().

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:19 -08:00