Commit Graph

2443 Commits

Author SHA1 Message Date
Nick Piggin 30002ed2e4 mm: readahead scan lockless
radix_tree_next_hole() is implemented as a series of radix_tree_lookup()s.
So it can be called locklessly, under rcu_read_lock().

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Reviewed-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>
2008-07-26 12:00:06 -07:00
Nick Piggin 8174c430e4 x86: lockless get_user_pages_fast()
Implement get_user_pages_fast without locking in the fastpath on x86.

Do an optimistic lockless pagetable walk, without taking mmap_sem or any
page table locks or even mmap_sem.  Page table existence is guaranteed by
turning interrupts off (combined with the fact that we're always looking
up the current mm, means we can do the lockless page table walk within the
constraints of the TLB shootdown design).  Basically we can do this
lockless pagetable walk in a similar manner to the way the CPU's pagetable
walker does not have to take any locks to find present ptes.

This patch (combined with the subsequent ones to convert direct IO to use
it) was found to give about 10% performance improvement on a 2 socket 8
core Intel Xeon system running an OLTP workload on DB2 v9.5

 "To test the effects of the patch, an OLTP workload was run on an IBM
  x3850 M2 server with 2 processors (quad-core Intel Xeon processors at
  2.93 GHz) using IBM DB2 v9.5 running Linux 2.6.24rc7 kernel.  Comparing
  runs with and without the patch resulted in an overall performance
  benefit of ~9.8%.  Correspondingly, oprofiles showed that samples from
  __up_read and __down_read routines that is seen during thread contention
  for system resources was reduced from 2.8% down to .05%.  Monitoring the
  /proc/vmstat output from the patched run showed that the counter for
  fast_gup contained a very high number while the fast_gup_slow value was
  zero."

(fast_gup is the old name for get_user_pages_fast, fast_gup_slow is a
counter we had for the number of times the slowpath was invoked).

The main reason for the improvement is that DB2 has multiple threads each
issuing direct-IO.  Direct-IO uses get_user_pages, and thus the threads
contend the mmap_sem cacheline, and can also contend on page table locks.

I would anticipate larger performance gains on larger systems, however I
think DB2 uses an adaptive mix of threads and processes, so it could be
that thread contention remains pretty constant as machine size increases.
In which case, we stuck with "only" a 10% gain.

The downside of using get_user_pages_fast is that if there is not a pte
with the correct permissions for the access, we end up falling back to
get_user_pages and so the get_user_pages_fast is a bit of extra work.
However this should not be the common case in most performance critical
code.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: Kconfig fix]
[akpm@linux-foundation.org: Makefile fix/cleanup]
[akpm@linux-foundation.org: warning fix]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Reviewed-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>
2008-07-26 12:00:06 -07:00
Nishanth Aravamudan 8a21346058 hugetlb: fix CONFIG_SYSCTL=n build
Fixes a build failure reported by Alan Cox:

mm/hugetlb.c: In function `hugetlb_acct_memory': mm/hugetlb.c:1507:
error: implicit declaration of function `cpuset_mems_nr'

Also reverts Ingo's

    commit e44d1b2998
    Author: Ingo Molnar <mingo@elte.hu>
    Date:   Fri Jul 25 12:57:41 2008 +0200

        mm/hugetlb.c: fix build failure with !CONFIG_SYSCTL

which fixed the build error but added some unused-static-function warnings.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:01 -07:00
Andrew Morton 16d69265b9 uninline arch_pick_mmap_layout()
Fix this, on avr32:

  include/linux/utsname.h:35,
                   from init/main.c:20:
  include/linux/sched.h: In function 'arch_pick_mmap_layout':
  include/linux/sched.h:2149: error: implicit declaration of function 'PAGE_ALIGN'

Reported-by: Adrian Bunk <bunk@kernel.org>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:01 -07:00
Ingo Molnar e44d1b2998 mm/hugetlb.c: fix build failure with !CONFIG_SYSCTL
on !CONFIG_SYSCTL on x86 with latest -git i get:

     mm/hugetlb.c: In function 'decrement_hugepage_resv_vma':
     mm/hugetlb.c:83: error: 'reserve' undeclared (first use in this function)
     mm/hugetlb.c:83: error: (Each undeclared identifier is reported only once
     mm/hugetlb.c:83: error: for each function it appears in.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 11:35:41 -07:00
Keika Kobayashi 873b477177 per-task-delay-accounting: add memory reclaim delay
Sometimes, application responses become bad under heavy memory load.
Applications take a bit time to reclaim memory.  The statistics, how long
memory reclaim takes, will be useful to measure memory usage.

This patch adds accounting memory reclaim to per-task-delay-accounting for
accounting the time of do_try_to_free_pages().

<i.e>

- When System is under low memory load,
  memory reclaim may not occur.

$ free
             total       used       free     shared    buffers     cached
Mem:       8197800    1577300    6620500          0       4808    1516724
-/+ buffers/cache:      55768    8142032
Swap:     16386292          0   16386292

$ vmstat 1
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
 0  0      0 5069748  10612 3014060    0    0     0     0    3   26  0  0 100  0
 0  0      0 5069748  10612 3014060    0    0     0     0    4   22  0  0 100  0
 0  0      0 5069748  10612 3014060    0    0     0     0    3   18  0  0 100  0

Measure the time of tar command.

$ ls -s test.dat
1501472 test.dat

$ time tar cvf test.tar test.dat
real    0m13.388s
user    0m0.116s
sys     0m5.304s

$ ./delayget -d -p <pid>
CPU             count     real total  virtual total    delay total
                  428     5528345500     5477116080       62749891
IO              count    delay total
                  338     8078977189
SWAP            count    delay total
                    0              0
RECLAIM         count    delay total
                    0              0

- When system is under heavy memory load
  memory reclaim may occur.

$ vmstat 1
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
 0  0 7159032  49724   1812   3012    0    0     0     0    3   24  0  0 100  0
 0  0 7159032  49724   1812   3012    0    0     0     0    4   24  0  0 100  0
 0  0 7159032  49848   1812   3012    0    0     0     0    3   22  0  0 100  0

In this case, one process uses more 8G memory
by execution of malloc() and memset().

$ time tar cvf test.tar test.dat
real    1m38.563s        <-  increased by 85 sec
user    0m0.140s
sys     0m7.060s

$ ./delayget -d -p <pid>
CPU             count     real total  virtual total    delay total
                 9021     7140446250     7315277975      923201824
IO              count    delay total
                 8965    90466349669
SWAP            count    delay total
                    3       21036367
RECLAIM         count    delay total
                  740    61011951153

In the later case, the value of RECLAIM is increasing.
So, taskstats can show how much memory reclaim influences TAT.

Signed-off-by: Keika Kobayashi <kobayashi.kk@ncos.nec.co.jp>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujistu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:47 -07:00
KAMEZAWA Hiroyuki 628f423553 memcg: limit change shrink usage
Shrinking memory usage at limit change.

[akpm@linux-foundation.org: coding-style fixes]
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>
2008-07-25 10:53:37 -07:00
Li Zefan cede86acd8 memcg: clean up checking of the disabled flag
Those checks are unnecessary, because when the subsystem is disabled
it can't be mounted, so those functions won't get called.

The check is needed in functions which will be called in other places
except cgroup.

[hugh@veritas.com: further checking of disabled flag]
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
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>
2008-07-25 10:53:37 -07:00
KAMEZAWA Hiroyuki accf163e6a memcg: remove a redundant check
Because of remove refcnt patch, it's very rare case to that
mem_cgroup_charge_common() is called against a page which is accounted.

mem_cgroup_charge_common() is called when.
 1. a page is added into file cache.
 2. an anon page is _newly_ mapped.

A racy case is that a newly-swapped-in anonymous page is referred from
prural threads in do_swap_page() at the same time.
(a page is not Locked when mem_cgroup_charge() is called from do_swap_page.)

Another case is shmem. It charges its page before calling add_to_page_cache().
Then, mem_cgroup_charge_cache() is called twice. This case is handled in
mem_cgroup_cache_charge(). But this check may be too hacky...

Signed-off-by : KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:37 -07:00
KAMEZAWA Hiroyuki b76734e5e3 memcg: add hints for branch
Showing brach direction for obvious conditions.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:37 -07:00
KAMEZAWA Hiroyuki c9b0ed5148 memcg: helper function for relcaim from shmem.
A new call, mem_cgroup_shrink_usage() is added for shmem handling and
relacing non-standard usage of mem_cgroup_charge/uncharge.

Now, shmem calls mem_cgroup_charge() just for reclaim some pages from
mem_cgroup.  In general, shmem is used by some process group and not for
global resource (like file caches).  So, it's reasonable to reclaim pages
from mem_cgroup where shmem is mainly used.

[hugh@veritas.com: shmem_getpage release page sooner]
[hugh@veritas.com: mem_cgroup_shrink_usage css_put]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
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>
2008-07-25 10:53:37 -07:00
KAMEZAWA Hiroyuki 69029cd550 memcg: remove refcnt from page_cgroup
memcg: performance improvements

Patch Description
 1/5 ... remove refcnt fron page_cgroup patch (shmem handling is fixed)
 2/5 ... swapcache handling patch
 3/5 ... add helper function for shmem's memory reclaim patch
 4/5 ... optimize by likely/unlikely ppatch
 5/5 ... remove redundunt check patch (shmem handling is fixed.)

Unix bench result.

== 2.6.26-rc2-mm1 + memory resource controller
Execl Throughput                           2915.4 lps   (29.6 secs, 3 samples)
C Compiler Throughput                      1019.3 lpm   (60.0 secs, 3 samples)
Shell Scripts (1 concurrent)               5796.0 lpm   (60.0 secs, 3 samples)
Shell Scripts (8 concurrent)               1097.7 lpm   (60.0 secs, 3 samples)
Shell Scripts (16 concurrent)               565.3 lpm   (60.0 secs, 3 samples)
File Read 1024 bufsize 2000 maxblocks    1022128.0 KBps  (30.0 secs, 3 samples)
File Write 1024 bufsize 2000 maxblocks   544057.0 KBps  (30.0 secs, 3 samples)
File Copy 1024 bufsize 2000 maxblocks    346481.0 KBps  (30.0 secs, 3 samples)
File Read 256 bufsize 500 maxblocks      319325.0 KBps  (30.0 secs, 3 samples)
File Write 256 bufsize 500 maxblocks     148788.0 KBps  (30.0 secs, 3 samples)
File Copy 256 bufsize 500 maxblocks       99051.0 KBps  (30.0 secs, 3 samples)
File Read 4096 bufsize 8000 maxblocks    2058917.0 KBps  (30.0 secs, 3 samples)
File Write 4096 bufsize 8000 maxblocks   1606109.0 KBps  (30.0 secs, 3 samples)
File Copy 4096 bufsize 8000 maxblocks    854789.0 KBps  (30.0 secs, 3 samples)
Dc: sqrt(2) to 99 decimal places         126145.2 lpm   (30.0 secs, 3 samples)

                     INDEX VALUES
TEST                                        BASELINE     RESULT      INDEX

Execl Throughput                                43.0     2915.4      678.0
File Copy 1024 bufsize 2000 maxblocks         3960.0   346481.0      875.0
File Copy 256 bufsize 500 maxblocks           1655.0    99051.0      598.5
File Copy 4096 bufsize 8000 maxblocks         5800.0   854789.0     1473.8
Shell Scripts (8 concurrent)                     6.0     1097.7     1829.5
                                                                 =========
     FINAL SCORE                                                     991.3

== 2.6.26-rc2-mm1 + this set ==
Execl Throughput                           3012.9 lps   (29.9 secs, 3 samples)
C Compiler Throughput                       981.0 lpm   (60.0 secs, 3 samples)
Shell Scripts (1 concurrent)               5872.0 lpm   (60.0 secs, 3 samples)
Shell Scripts (8 concurrent)               1120.3 lpm   (60.0 secs, 3 samples)
Shell Scripts (16 concurrent)               578.0 lpm   (60.0 secs, 3 samples)
File Read 1024 bufsize 2000 maxblocks    1003993.0 KBps  (30.0 secs, 3 samples)
File Write 1024 bufsize 2000 maxblocks   550452.0 KBps  (30.0 secs, 3 samples)
File Copy 1024 bufsize 2000 maxblocks    347159.0 KBps  (30.0 secs, 3 samples)
File Read 256 bufsize 500 maxblocks      314644.0 KBps  (30.0 secs, 3 samples)
File Write 256 bufsize 500 maxblocks     151852.0 KBps  (30.0 secs, 3 samples)
File Copy 256 bufsize 500 maxblocks      101000.0 KBps  (30.0 secs, 3 samples)
File Read 4096 bufsize 8000 maxblocks    2033256.0 KBps  (30.0 secs, 3 samples)
File Write 4096 bufsize 8000 maxblocks   1611814.0 KBps  (30.0 secs, 3 samples)
File Copy 4096 bufsize 8000 maxblocks    847979.0 KBps  (30.0 secs, 3 samples)
Dc: sqrt(2) to 99 decimal places         128148.7 lpm   (30.0 secs, 3 samples)

                     INDEX VALUES
TEST                                        BASELINE     RESULT      INDEX

Execl Throughput                                43.0     3012.9      700.7
File Copy 1024 bufsize 2000 maxblocks         3960.0   347159.0      876.7
File Copy 256 bufsize 500 maxblocks           1655.0   101000.0      610.3
File Copy 4096 bufsize 8000 maxblocks         5800.0   847979.0     1462.0
Shell Scripts (8 concurrent)                     6.0     1120.3     1867.2
                                                                 =========
     FINAL SCORE                                                    1004.6

This patch:

Remove refcnt from page_cgroup().

After this,

 * A page is charged only when !page_mapped() && no page_cgroup is assigned.
	* Anon page is newly mapped.
	* File page is added to mapping->tree.

 * A page is uncharged only when
	* Anon page is fully unmapped.
	* File page is removed from LRU.

There is no change in behavior from user's view.

This patch also removes unnecessary calls in rmap.c which was used only for
refcnt mangement.

[akpm@linux-foundation.org: fix warning]
[hugh@veritas.com: fix shmem_unuse_inode charging]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
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>
2008-07-25 10:53:37 -07:00
KAMEZAWA Hiroyuki e8589cc189 memcg: better migration handling
This patch changes page migration under memory controller to use a
different algorithm.  (thanks to Christoph for new idea.)

Before:
 - page_cgroup is migrated from an old page to a new page.
After:
 - a new page is accounted , no reuse of page_cgroup.

Pros:

 - We can avoid compliated lock depndencies and races in migration.

Cons:

 - new param to mem_cgroup_charge_common().

 - mem_cgroup_getref() is added for handling ref_cnt ping-pong.

This version simplifies complicated lock dependency in page migraiton
under memory resource controller.

  new refcnt sequence is following.

a mapped page:
  prepage_migration() ..... +1 to NEW page
  try_to_unmap()      ..... all refs to OLD page is gone.
  move_pages()        ..... +1 to NEW page if page cache.
  remap...            ..... all refs from *map* is added to NEW one.
  end_migration()     ..... -1 to New page.

  page's mapcount + (page_is_cache) refs are added to NEW one.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:37 -07:00
KAMEZAWA Hiroyuki 508b7be0a5 memcg: avoid unnecessary initialization
* remove over-killing initialization (in fast path)
* makeing the condition for PAGE_CGROUP_FLAG_ACTIVE be more obvious.

Signed-off-by: KAMEAZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:37 -07:00
KAMEZAWA Hiroyuki a181b0e888 memcg: make global var read_mostly
mem_cgroup_subsys and page_cgroup_cache should be read_mostly and
MEM_CGROUP_RECLAIM_RETRIES can be just a fixed number.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:37 -07:00
Paul Menage 856c13aa1f cgroup files: convert res_counter_write() to be a cgroups write_string() handler
Currently res_counter_write() is a raw file handler even though it's
ultimately taking a number, since in some cases it wants to
pre-process the string when converting it to a number.

This patch converts res_counter_write() from a raw file handler to a
write_string() handler; this allows some of the boilerplate
copying/locking/checking to be removed, and simplies the cleanup path,
since these functions are now performed by the cgroups framework.

[lizf@cn.fujitsu.com: build fix]
Signed-off-by: Paul Menage <menage@google.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:36 -07:00
Mingming Cao 3f31fddfa2 jbd: fix race between free buffer and commit transaction
journal_try_to_free_buffers() could race with jbd commit transaction when
the later is holding the buffer reference while waiting for the data
buffer to flush to disk.  If the caller of journal_try_to_free_buffers()
request tries hard to release the buffers, it will treat the failure as
error and return back to the caller.  We have seen the directo IO failed
due to this race.  Some of the caller of releasepage() also expecting the
buffer to be dropped when passed with GFP_KERNEL mask to the
releasepage()->journal_try_to_free_buffers().

With this patch, if the caller is passing the __GFP_WAIT and __GFP_FS to
indicating this call could wait, in case of try_to_free_buffers() failed,
let's waiting for journal_commit_transaction() to finish commit the
current committing transaction, then try to free those buffers again.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Reviewed-by: Badari Pulavarty <pbadari@us.ibm.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:32 -07:00
OGAWA Hirofumi 2b4bc46052 pdflush: use time_after() instead of open-coding it
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:28 -07:00
Hugh Dickins 78ecba0812 mm: fix ever-decreasing swap priority
Vegard Nossum has noticed the ever-decreasing negative priority in a
swapon /swapoff loop, which eventually would misprioritize when int wraps
positive.  Not worth spending much code on, but probably better fixed.

It's easy to handle the swapping on and off of just one area, but there's
not much point if a pair or more still misbehave.  To handle the general
case, swapoff should compact negative priorities, keeping them always from
-1 to -MAX_SWAPFILES.  That's a change, but should cause no regression,
since these negative (unspecified) priorities are disjoint from the the
positive specified priorities 0 to 32767.

One small functional difference, which seems appropriate: when swapoff
fails to free all swap from a negative priority area, that area is now
reinserted at lowest priority, rather than at its original priority.

In moving down swapon's setting of priority, I notice that an area is
visible to /proc/swaps when it has swap_map set, yet that was being set
before all the visible fields were properly filled in: corrected.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:21 -07:00
Gerald Schaefer 83d1674a94 mm: make CONFIG_MIGRATION available w/o CONFIG_NUMA
We'd like to support CONFIG_MEMORY_HOTREMOVE on s390, which depends on
CONFIG_MIGRATION.  So far, CONFIG_MIGRATION is only available with NUMA
support.

This patch makes CONFIG_MIGRATION selectable for architectures that define
ARCH_ENABLE_MEMORY_HOTREMOVE.  When MIGRATION is enabled w/o NUMA, the
kernel won't compile because migrate_vmas() does not know about
vm_ops->migrate() and vma_migratable() does not know about policy_zone.
To fix this, those two functions can be restricted to '#ifdef CONFIG_NUMA'
because they are not being used w/o NUMA.  vma_migratable() is moved over
from migrate.h to mempolicy.h.

[kosaki.motohiro@jp.fujitsu.com: build fix]
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: KOSAKI Motorhiro <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 10:47:21 -07:00
Badari Pulavarty 5c755e9fd8 memory-hotplug: add sysfs removable attribute for hotplug memory remove
Memory may be hot-removed on a per-memory-block basis, particularly on
POWER where the SPARSEMEM section size often matches the memory-block
size.  A user-level agent must be able to identify which sections of
memory are likely to be removable before attempting the potentially
expensive operation.  This patch adds a file called "removable" to the
memory directory in sysfs to help such an agent.  In this patch, a memory
block is considered removable if;

o It contains only MOVABLE pageblocks
o It contains only pageblocks with free pages regardless of pageblock type

On the other hand, a memory block starting with a PageReserved() page will
never be considered removable.  Without this patch, the user-agent is
forced to choose a memory block to remove randomly.

Sample output of the sysfs files:

./memory/memory0/removable: 0
./memory/memory1/removable: 0
./memory/memory2/removable: 0
./memory/memory3/removable: 0
./memory/memory4/removable: 0
./memory/memory5/removable: 0
./memory/memory6/removable: 0
./memory/memory7/removable: 1
./memory/memory8/removable: 0
./memory/memory9/removable: 0
./memory/memory10/removable: 0
./memory/memory11/removable: 0
./memory/memory12/removable: 0
./memory/memory13/removable: 0
./memory/memory14/removable: 0
./memory/memory15/removable: 0
./memory/memory16/removable: 0
./memory/memory17/removable: 1
./memory/memory18/removable: 1
./memory/memory19/removable: 1
./memory/memory20/removable: 1
./memory/memory21/removable: 1
./memory/memory22/removable: 1

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
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>
2008-07-24 10:47:21 -07:00
Kent Liu 2f7f24eca3 memory-hotplug: don't calculate vm_total_pages twice when rebuilding zonelists in online_pages()
If zonelist is required to be rebuilt in online_pages(), there is no need
to recalculate vm_total_pages in that function, as it has been updated in
the call build_all_zonelists().

Signed-off-by: Kent Liu <kent.liu@linux.intel.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
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 10:47:21 -07:00
Yasunori Goto af370fb8cb memory hotplug: small fixes to bootmem freeing for memory hotremove
- Change some naming
  * Magic -> types
  * MIX_INFO -> MIX_SECTION_INFO
  * Change definition of bootmem type from direct hex value

- __free_pages_bootmem() becomes __meminit.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: 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 10:47:21 -07:00
Yasunori Goto 48c906823f 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
as much as possible.  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: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: David Miller <davem@davemloft.net>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hiroyuki KAMEZAWA <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:21 -07:00
Vegard Nossum f84f9504bd mm: remove initialization of static per-cpu variables
This was required by some old, no-longer-used gcc on sparc.

Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:21 -07:00
Adrian Bunk d92bc31854 mm: make register_page_bootmem_info_section() static
Make the needlessly global register_page_bootmem_info_section() static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: 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>
2008-07-24 10:47:21 -07:00
Adrian Bunk b69a7288ea mm/page_alloc.c: cleanups
This patch contains the following cleanups:
- make the following needlessly global variables static:
  - required_kernelcore
  - zone_movable_pfn[]
- make the following needlessly global functions static:
  - move_freepages()
  - move_freepages_block()
  - setup_pageset()
  - find_usable_zone_for_movable()
  - adjust_zone_range_for_zone_movable()
  - __absent_pages_in_range()
  - find_min_pfn_for_node()
  - find_zone_movable_pfns_for_nodes()

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 10:47:20 -07:00
Timur Tabi 2be0ffe2b2 mm: add alloc_pages_exact() and free_pages_exact()
alloc_pages_exact() is similar to alloc_pages(), except that it allocates
the minimum number of pages to fulfill the request.  This is useful if you
want to allocate a very large buffer that is slightly larger than an even
power-of-two number of pages.  In that case, alloc_pages() will waste a
lot of memory.

I have a video driver that wants to allocate a 5MB buffer.  alloc_pages()
wiill waste 3MB of physically-contiguous memory.

Signed-off-by: Timur Tabi <timur@freescale.com>
Cc: Andi Kleen <andi@firstfloor.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>
2008-07-24 10:47:20 -07:00
Johannes Weiner 3560e249ab bootmem: replace node_boot_start in struct bootmem_data
Almost all users of this field need a PFN instead of a physical address,
so replace node_boot_start with node_min_pfn.

[Lee.Schermerhorn@hp.com: fix spurious BUG_ON() in mark_bootmem()]
Signed-off-by: Johannes Weiner <hannes@saeureba.de>
Cc: <linux-arch@vger.kernel.org>
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>
2008-07-24 10:47:20 -07:00
Johannes Weiner 75a56cfe9f bootmem: revisit alloc_bootmem_section
Since alloc_bootmem_core does no goal-fallback anymore and just returns
NULL if the allocation fails, we might now use it in alloc_bootmem_section
without all the fixup code for a misplaced allocation.

Also, the limit can be the first PFN of the next section as the semantics
is that the limit is _above_ the allocated region, not within.

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
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>
2008-07-24 10:47:20 -07:00
Johannes Weiner 4cc278b721 bootmem: Make __alloc_bootmem_low_node fall back to other nodes
__alloc_bootmem_node already does this, make the interface consistent.

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:20 -07:00
Johannes Weiner 0f3caba211 bootmem: respect goal more likely
The old node-agnostic code tried allocating on all nodes starting from the
one with the lowest range.  alloc_bootmem_core retried without the goal if
it could not satisfy it and so the goal was only respected at all when it
happened to be on the first (lowest page numbers) node (or theoretically
if allocations failed on all nodes before to the one holding the goal).

Introduce a non-panicking helper that starts allocating from the node
holding the goal and falls back only after all thes tries failed, thus
moving the goal fallback code out of alloc_bootmem_core.

Make all other allocation functions benefit from this new helper.

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
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>
2008-07-24 10:47:20 -07:00
Johannes Weiner e2bf3cae51 bootmem: factor out the marking of a PFN range
Introduce new helpers that mark a range that resides completely on a node
or node-agnostic ranges that might also span node boundaries.

The free/reserve API functions will then directly use these helpers.

Note that the free/reserve semantics become more strict: while the prior
code took basically arbitrary range arguments and marked the PFNs that
happen to fall into that range, the new code requires node-specific ranges
to be completely on the node.  The node-agnostic requests might span node
boundaries as long as the nodes are contiguous.

Passing ranges that do not satisfy these criteria is a bug.

[akpm@linux-foundation.org: fix printk warnings]
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:20 -07:00
Johannes Weiner d747fa4bce bootmem: free/reserve helpers
Factor out the common operation of marking a range on the bitmap.

[akpm@linux-foundation.org: fix various warnings]
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:20 -07:00
Johannes Weiner 5f2809e69c bootmem: clean up alloc_bootmem_core
alloc_bootmem_core has become quite nasty to read over time.  This is a
clean rewrite that keeps the semantics.

bdata->last_pos has been dropped.

bdata->last_success has been renamed to hint_idx and it is now an index
relative to the node's range.  Since further block searching might start
at this index, it is now set to the end of a succeeded allocation rather
than its beginning.

bdata->last_offset has been renamed to last_end_off to be more clear that
it represents the ending address of the last allocation relative to the
node.

[y-goto@jp.fujitsu.com: fix new alloc_bootmem_core()]
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Signed-off-by: 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>
2008-07-24 10:47:20 -07:00
Johannes Weiner 41546c1741 bootmem: clean up free_all_bootmem_core
Rewrite the code in a more concise way using less variables.

[akpm@linux-foundation.org: fix printk warnings]
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:20 -07:00
Johannes Weiner 636cc40cb7 bootmem: revisit bootmem descriptor list handling
link_bootmem handles an insertion of a new descriptor into the sorted list
in more or less three explicit branches; empty list, insert in between and
append.  These cases can be expressed implicite.

Also mark the sorted list as initdata as it can be thrown away after boot
as well.

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 10:47:20 -07:00
Johannes Weiner df049a5f41 bootmem: revisit bitmap size calculations
Reincarnate get_mapsize as bootmap_bytes and implement
bootmem_bootmap_pages on top of it.

Adjust users of these helpers and make free_all_bootmem_core use
bootmem_bootmap_pages instead of open-coding it.

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 10:47:20 -07:00
Johannes Weiner 2e5237daf0 bootmem: add debugging framework
Introduce the bootmem_debug kernel parameter that enables very verbose
diagnostics regarding all range operations of bootmem as well as the
initialization and release of nodes.

[akpm@linux-foundation.org: fix printk warnings]
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 10:47:20 -07:00
Johannes Weiner a66fd7daec bootmem: add documentation to API functions
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 10:47:19 -07:00
Johannes Weiner 57cfc29efa bootmem: clean up bootmem.c file header
Change the description, move a misplaced comment about the allocator
itself and add me to the list of copyright holders.

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
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 10:47:19 -07:00
Johannes Weiner 223e8dc924 bootmem: reorder code to match new bootmem structure
This only reorders functions so that further patches will be easier to
read.  No code changed.

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 10:47:19 -07:00
Adam Litke 7251ff78b9 hugetlb: quota is not freed for unused reserved private huge pages
With shared reservations (and now also with private reservations), we reserve
huge pages at mmap time.  We also account for the mapping against fs quota to
prevent a reservation from being preempted by quota exhaustion.

When testing with the libhugetlbfs test suite, I found a problem with quota
accounting.  FS quota for allocated pages is handled correctly but we are not
releasing quota for private pages that were reserved but never allocated.  Do
this in hugetlb_vm_op_close() at the same time as unused page reservations are
released.

Signed-off-by: Adam Litke <agl@us.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@saeurebad.de>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Hugh Dickins <hugh@veritas.com>
Acked-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 10:47:19 -07:00
Mel Gorman 7f09ca51e9 hugetlb: fix a hugepage reservation check for MAP_SHARED
When removing a huge page from the hugepage pool for a fault the system checks
to see if the mapping requires additional pages to be reserved, and if it does
whether there are any unreserved pages remaining.  If not, the allocation
fails without even attempting to get a page.  In order to determine whether to
apply this check we call vma_has_private_reserves() which tells us if this vma
is MAP_PRIVATE and is the owner.  This incorrectly triggers the remaining
reservation test for MAP_SHARED mappings which prevents allocation of the
final page in the pool even though it is reserved for this mapping.

In reality we only want to check this for MAP_PRIVATE mappings where the
process is not the original mapper.  Replace vma_has_private_reserves() with
vma_has_reserves() which indicates whether further reserves are required, and
update the caller.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Adam Litke <agl@us.ibm.com>
Acked-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 10:47:19 -07:00
Jon Tollefson 53ba51d21d hugetlb: allow arch overridden hugepage allocation
Allow alloc_bootmem_huge_page() to be overridden by architectures that
can't always use bootmem.  This requires huge_boot_pages to be available
for use by this function.

This is required for powerpc 16G pages, which have to be reserved prior to
boot-time.  The location of these pages are indicated in the device tree.

Acked-by: Adam Litke <agl@us.ibm.com>
Signed-off-by: Jon Tollefson <kniht@linux.vnet.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>
2008-07-24 10:47:19 -07:00
Nick Piggin e11bfbfcb0 hugetlb: override default huge page size
Allow configurations with the default huge page size which is different to
the traditional HPAGE_SIZE size.  The default huge page size is the one
represented in the legacy /proc ABIs, SHM, and which is defaulted to when
mounting hugetlbfs filesystems.

This is implemented with a new kernel option default_hugepagesz=, which
defaults to HPAGE_SIZE if not specified.

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>
2008-07-24 10:47:19 -07:00
Andi Kleen ceb8687961 hugetlb: introduce pud_huge
Straight forward extensions for huge pages located in the PUD instead of
PMDs.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
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>
2008-07-24 10:47:18 -07:00
Andi Kleen 4abd32dbab hugetlb: printk cleanup
- Reword sentence to clarify meaning with multiple options
- Add support for using GB prefixes for the page size
- Add extra printk to delayed > MAX_ORDER allocation code

Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
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>
2008-07-24 10:47:18 -07:00
Andi Kleen 8faa8b077b hugetlb: support boot allocate different sizes
Make some infrastructure changes to allow boot-time allocation of
different hugepage page sizes.

- move all basic hstate initialisation into hugetlb_add_hstate
- create a new function hugetlb_hstate_alloc_pages() to do the
  actual initial page allocations. Call this function early in
  order to allocate giant pages from bootmem.
- Check for multiple hugepages= parameters

Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Acked-by: Andrew Hastings <abh@cray.com>
Signed-off-by: Andi Kleen <ak@suse.de>
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>
2008-07-24 10:47:18 -07:00
Andi Kleen aa888a7497 hugetlb: support larger than MAX_ORDER
This is needed on x86-64 to handle GB pages in hugetlbfs, because it is
not practical to enlarge MAX_ORDER to 1GB.

Instead the 1GB pages are only allocated at boot using the bootmem
allocator using the hugepages=...  option.

These 1G bootmem pages are never freed.  In theory it would be possible to
implement that with some complications, but since it would be a one-way
street (>= MAX_ORDER pages cannot be allocated later) I decided not to
currently.

The >= MAX_ORDER code is not ifdef'ed per architecture.  It is not very
big and the ifdef uglyness seemed not be worth it.

Known problems: /proc/meminfo and "free" do not display the memory
allocated for gb pages in "Total".  This is a little confusing for the
user.

Acked-by: Andrew Hastings <abh@cray.com>
Signed-off-by: Andi Kleen <ak@suse.de>
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>
2008-07-24 10:47:18 -07:00
Andi Kleen 01ad1c0827 mm: export prep_compound_page to mm
hugetlb will need to get compound pages from bootmem to handle the case of
them being greater than or equal to MAX_ORDER.  Export the constructor
function needed for this.

Acked-by: Adam Litke <agl@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
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>
2008-07-24 10:47:17 -07:00
Andi Kleen b54bbf7b81 mm: introduce non panic alloc_bootmem
Straight forward variant of the existing __alloc_bootmem_node, only
subsequent patch when allocating giant hugepages at boot -- don't want to
panic if we can't allocate as many as the user asked for.

Signed-off-by: Andi Kleen <ak@suse.de>
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>
2008-07-24 10:47:17 -07:00
Andi Kleen 5ced66c901 hugetlb: abstract numa round robin selection
Need this as a separate function for a future patch.

No behaviour change.

Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
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>
2008-07-24 10:47:17 -07:00
Nishanth Aravamudan a343787016 hugetlb: new sysfs interface
Provide new hugepages user APIs that are more suited to multiple hstates
in sysfs.  There is a new directory, /sys/kernel/hugepages.  Underneath
that directory there will be a directory per-supported hugepage size,
e.g.:

/sys/kernel/hugepages/hugepages-64kB
/sys/kernel/hugepages/hugepages-16384kB
/sys/kernel/hugepages/hugepages-16777216kB

corresponding to 64k, 16m and 16g respectively.  Within each
hugepages-size directory there are a number of files, corresponding to the
tracked counters in the hstate, e.g.:

/sys/kernel/hugepages/hugepages-64/nr_hugepages
/sys/kernel/hugepages/hugepages-64/nr_overcommit_hugepages
/sys/kernel/hugepages/hugepages-64/free_hugepages
/sys/kernel/hugepages/hugepages-64/resv_hugepages
/sys/kernel/hugepages/hugepages-64/surplus_hugepages

Of these files, the first two are read-write and the latter three are
read-only.  The size of the hugepage being manipulated is trivially
deducible from the enclosing directory and is always expressed in kB (to
match meminfo).

[dave@linux.vnet.ibm.com: fix build]
[nacc@us.ibm.com: hugetlb: hang off of /sys/kernel/mm rather than /sys/kernel]
[nacc@us.ibm.com: hugetlb: remove CONFIG_SYSFS dependency]
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-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>
2008-07-24 10:47:17 -07:00
Andi Kleen a137e1cc6d hugetlbfs: per mount huge page sizes
Add the ability to configure the hugetlb hstate used on a per mount basis.

- Add a new pagesize= option to the hugetlbfs mount that allows setting
  the page size
- This option causes the mount code to find the hstate corresponding to the
  specified size, and sets up a pointer to the hstate in the mount's
  superblock.
- Change the hstate accessors to use this information rather than the
  global_hstate they were using (requires a slight change in mm/memory.c
  so we don't NULL deref in the error-unmap path -- see comments).

[np: take hstate out of hugetlbfs inode and vma->vm_private_data]

Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
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>
2008-07-24 10:47:17 -07:00
Andi Kleen e5ff215941 hugetlb: multiple hstates for multiple page sizes
Add basic support for more than one hstate in hugetlbfs.  This is the key
to supporting multiple hugetlbfs page sizes at once.

- Rather than a single hstate, we now have an array, with an iterator
- default_hstate continues to be the struct hstate which we use by default
- Add functions for architectures to register new hstates

[akpm@linux-foundation.org: coding-style fixes]
Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
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>
2008-07-24 10:47:17 -07:00
Andi Kleen a551643895 hugetlb: modular state for hugetlb page size
The goal of this patchset is to support multiple hugetlb page sizes.  This
is achieved by introducing a new struct hstate structure, which
encapsulates the important hugetlb state and constants (eg.  huge page
size, number of huge pages currently allocated, etc).

The hstate structure is then passed around the code which requires these
fields, they will do the right thing regardless of the exact hstate they
are operating on.

This patch adds the hstate structure, with a single global instance of it
(default_hstate), and does the basic work of converting hugetlb to use the
hstate.

Future patches will add more hstate structures to allow for different
hugetlbfs mounts to have different page sizes.

[akpm@linux-foundation.org: coding-style fixes]
Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
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>
2008-07-24 10:47:17 -07:00
Andi Kleen b7ba30c679 hugetlb: factor out prep_new_huge_page
Needed to avoid code duplication in follow up patches.

Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
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>
2008-07-24 10:47:17 -07:00
Nishanth Aravamudan ff7ea79cf7 mm: create /sys/kernel/mm
Add a kobject to create /sys/kernel/mm when sysfs is mounted.  The kobject
will exist regardless.  This will allow for the hugepage related sysfs
directories to exist under the mm "subsystem" directory.  Add an ABI file
appropriately.

[kosaki.motohiro@jp.fujitsu.com: fix build]
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: 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 10:47:17 -07:00
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 7aa413def7 x86, MM: virtual address debug, cleanups
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-19 13:33:11 +02:00