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197 commits

Author SHA1 Message Date
Michal Hocko
778d3b0ff0 cpusets: randomize node rotor used in cpuset_mem_spread_node()
[ This patch has already been accepted as commit 0ac0c0d0f8 but later
  reverted (commit 35926ff5fb) because it itroduced arch specific
  __node_random which was defined only for x86 code so it broke other
  archs.  This is a followup without any arch specific code.  Other than
  that there are no functional changes.]

Some workloads that create a large number of small files tend to assign
too many pages to node 0 (multi-node systems).  Part of the reason is
that the rotor (in cpuset_mem_spread_node()) used to assign nodes starts
at node 0 for newly created tasks.

This patch changes the rotor to be initialized to a random node number
of the cpuset.

[akpm@linux-foundation.org: fix layout]
[Lee.Schermerhorn@hp.com: Define stub numa_random() for !NUMA configuration]
[mhocko@suse.cz: Make it arch independent]
[akpm@linux-foundation.org: fix CONFIG_NUMA=y, MAX_NUMNODES>1 build]
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Paul Menage <menage@google.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Paul Menage <menage@google.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26 16:49:43 -07:00
Stephen Wilson
f69ff943df mm: proc: move show_numa_map() to fs/proc/task_mmu.c
Moving show_numa_map() from mempolicy.c to task_mmu.c solves several
issues.

  - Having the show() operation "miles away" from the corresponding
    seq_file iteration operations is a maintenance burden.

  - The need to export ad hoc info like struct proc_maps_private is
    eliminated.

  - The implementation of show_numa_map() can be improved in a simple
    manner by cooperating with the other seq_file operations (start,
    stop, etc) -- something that would be messy to do without this
    change.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.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>
2011-05-25 08:39:34 -07:00
Stephen Wilson
9840e37239 mm: remove check_huge_range()
This function has been superseded by gather_hugetbl_stats() and is no
longer needed.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.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>
2011-05-25 08:39:33 -07:00
Stephen Wilson
722e2ee09b mm: make gather_stats() type-safe and remove forward declaration
Improve the prototype of gather_stats() to take a struct numa_maps as
argument instead of a generic void *.  Update all callers to make the
required type explicit.

Since gather_stats() is not needed before its definition and is scheduled
to be moved out of mempolicy.c the declaration is removed as well.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.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>
2011-05-25 08:39:33 -07:00
Stephen Wilson
b1f72d1857 mm: remove MPOL_MF_STATS
Mapping statistics in a NUMA environment is now computed using the generic
walk_page_range() logic.  Remove the old/equivalent functionality.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.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>
2011-05-25 08:39:33 -07:00
Stephen Wilson
29ea2f6982 mm: use walk_page_range() instead of custom page table walking code
Converting show_numa_map() to use the generic routine decouples the
function from mempolicy.c, allowing it to be moved out of the mm subsystem
and into fs/proc.

Also, include KSM pages in /proc/pid/numa_maps statistics.  The pagewalk
logic implemented by check_pte_range() failed to account for such pages as
they were not applicable to the page migration case.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.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>
2011-05-25 08:39:32 -07:00
Stephen Wilson
d98f6cb67f mm: export get_vma_policy()
In commit 48fce3429d ("mempolicies: unexport get_vma_policy()")
get_vma_policy() was marked static as all clients were local to
mempolicy.c.

However, the decision to generate /proc/pid/numa_maps in the numa memory
policy code and outside the procfs subsystem introduces an artificial
interdependency between the two systems.  Exporting get_vma_policy() once
again is the first step to clean up this interdependency.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.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>
2011-05-25 08:39:32 -07:00
Namhyung Kim
7571966189 mempolicy: remove redundant check in __mpol_equal()
The 'flags' field is already checked, no need to do it again.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Bob Liu <lliubbo@gmail.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Reviewed-by: Minchan Kim <minchan.kim@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>
2011-03-22 17:44:04 -07:00
Linus Torvalds
e16b396ce3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (47 commits)
  doc: CONFIG_UNEVICTABLE_LRU doesn't exist anymore
  Update cpuset info & webiste for cgroups
  dcdbas: force SMI to happen when expected
  arch/arm/Kconfig: remove one to many l's in the word.
  asm-generic/user.h: Fix spelling in comment
  drm: fix printk typo 'sracth'
  Remove one to many n's in a word
  Documentation/filesystems/romfs.txt: fixing link to genromfs
  drivers:scsi Change printk typo initate -> initiate
  serial, pch uart: Remove duplicate inclusion of linux/pci.h header
  fs/eventpoll.c: fix spelling
  mm: Fix out-of-date comments which refers non-existent functions
  drm: Fix printk typo 'failled'
  coh901318.c: Change initate to initiate.
  mbox-db5500.c Change initate to initiate.
  edac: correct i82975x error-info reported
  edac: correct i82975x mci initialisation
  edac: correct commented info
  fs: update comments to point correct document
  target: remove duplicate include of target/target_core_device.h from drivers/target/target_core_hba.c
  ...

Trivial conflict in fs/eventpoll.c (spelling vs addition)
2011-03-18 10:37:40 -07:00
Andi Kleen
5c4b4be3b6 mm: use correct numa policy node for transparent hugepages
Pass down the correct node for a transparent hugepage allocation.  Most
callers continue to use the current node, however the hugepaged daemon
now uses the previous node of the first to be collapsed page instead.
This ensures that khugepaged does not mess up local memory for an
existing process which uses local policy.

The choice of node is somewhat primitive currently: it just uses the
node of the first page in the pmd range.  An alternative would be to
look at multiple pages and use the most popular node.  I used the
simplest variant for now which should work well enough for the case of
all pages being on the same node.

[akpm@linux-foundation.org: coding-style fixes]
Acked-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Reviewed-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>
2011-03-04 17:53:39 -08:00
Andi Kleen
2f5f9486f8 mm: change alloc_pages_vma to pass down the policy node for local policy
Currently alloc_pages_vma() always uses the local node as policy node for
the LOCAL policy.  Pass this node down as an argument instead.

No behaviour change from this patch, but will be needed for followons.

Acked-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Reviewed-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>
2011-03-04 17:53:39 -08:00
Justin P. Mattock
ae0e47f02a Remove one to many n's in a word
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-03-01 15:47:58 +01:00
Andi Kleen
8eac563c1c thp: fix interleaving for transparent hugepages
The THP code didn't pass the correct interleaving shift to the memory
policy code.  Fix this here by adjusting for the order.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Acked-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-25 15:07:37 -08:00
Andrea Arcangeli
0bbbc0b33d thp: add numa awareness to hugepage allocations
It's mostly a matter of replacing alloc_pages with alloc_pages_vma after
introducing alloc_pages_vma.  khugepaged needs special handling as the
allocation has to happen inside collapse_huge_page where the vma is known
and an error has to be returned to the outer loop to sleep
alloc_sleep_millisecs in case of failure.  But it retains the more
efficient logic of handling allocation failures in khugepaged in case of
CONFIG_NUMA=n.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:45 -08:00
Andrea Arcangeli
bae9c19bf1 thp: split_huge_page_mm/vma
split_huge_page_pmd compat code.  Each one of those would need to be
expanded to hundred of lines of complex code without a fully reliable
split_huge_page_pmd design.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:41 -08:00
KOSAKI Motohiro
1e50df39f6 mempolicy: remove tasklist_lock from migrate_pages
Today, tasklist_lock in migrate_pages doesn't protect anything.
rcu_read_lock() provide enough protection from pid hash walk.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: Peter Zijlstra <peterz@infradead.org>
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>
2011-01-13 17:32:36 -08:00
Mel Gorman
7f0f24967b mm: migration: cleanup migrate_pages API by matching types for offlining and sync
With the introduction of the boolean sync parameter, the API looks a
little inconsistent as offlining is still an int.  Convert offlining to a
bool for the sake of being tidy.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:34 -08:00
Mel Gorman
77f1fe6b08 mm: migration: allow migration to operate asynchronously and avoid synchronous compaction in the faster path
Migration synchronously waits for writeback if the initial passes fails.
Callers of memory compaction do not necessarily want this behaviour if the
caller is latency sensitive or expects that synchronous migration is not
going to have a significantly better success rate.

This patch adds a sync parameter to migrate_pages() allowing the caller to
indicate if wait_on_page_writeback() is allowed within migration or not.
For reclaim/compaction, try_to_compact_pages() is first called
asynchronously, direct reclaim runs and then try_to_compact_pages() is
called synchronously as there is a greater expectation that it'll succeed.

[akpm@linux-foundation.org: build/merge fix]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:34 -08:00
Zeng Zhaoming
55cfaa3cbd mm/mempolicy.c: add rcu read lock to protect pid structure
find_task_by_vpid() should be protected by rcu_read_lock(), to prevent
free_pid() reclaiming pid.

Signed-off-by: Zeng Zhaoming <zengzm.kernel@gmail.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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>
2010-12-02 14:51:14 -08:00
Eric Dumazet
800416f799 numa: fix slab_node(MPOL_BIND)
When a node contains only HighMem memory, slab_node(MPOL_BIND)
dereferences a NULL pointer.

[ This code seems to go back all the way to commit 19770b3260: "mm:
  filter based on a nodemask as well as a gfp_mask".  Which was back in
  April 2008, and it got merged into 2.6.26.  - Linus ]

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28 10:04:30 -07:00
Vasiliy Kulikov
0def08e3ac mm/mempolicy.c: check return code of check_range
Function check_range may return ERR_PTR(...). Check for it.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Reviewed-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>
2010-10-26 16:52:06 -07:00
Minchan Kim
cf608ac19c mm: compaction: fix COMPACTPAGEFAILED counting
Presently update_nr_listpages() doesn't have a role.  That's because lists
passed is always empty just after calling migrate_pages.  The
migrate_pages cleans up page list which have failed to migrate before
returning by aaa994b3.

 [PATCH] page migration: handle freeing of pages in migrate_pages()

 Do not leave pages on the lists passed to migrate_pages().  Seems that we will
 not need any postprocessing of pages.  This will simplify the handling of
 pages by the callers of migrate_pages().

At that time, we thought we don't need any postprocessing of pages.  But
the situation is changed.  The compaction need to know the number of
failed to migrate for COMPACTPAGEFAILED stat

This patch makes new rule for caller of migrate_pages to call
putback_lru_pages.  So caller need to clean up the lists so it has a
chance to postprocess the pages.  [suggested by Christoph Lameter]

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Reviewed-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:06 -07:00
KOSAKI Motohiro
596d7cfa2b mempolicy: reduce stack size of migrate_pages()
migrate_pages() is using >500 bytes stack. Reduce it.

   mm/mempolicy.c: In function 'sys_migrate_pages':
   mm/mempolicy.c:1344: warning: the frame size of 528 bytes is larger than 512 bytes

[akpm@linux-foundation.org: don't play with a might-be-NULL pointer]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-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>
2010-08-09 20:44:58 -07:00
David Rientjes
6f48d0ebd9 oom: select task from tasklist for mempolicy ooms
The oom killer presently kills current whenever there is no more memory
free or reclaimable on its mempolicy's nodes.  There is no guarantee that
current is a memory-hogging task or that killing it will free any
substantial amount of memory, however.

In such situations, it is better to scan the tasklist for nodes that are
allowed to allocate on current's set of nodes and kill the task with the
highest badness() score.  This ensures that the most memory-hogging task,
or the one configured by the user with /proc/pid/oom_adj, is always
selected in such scenarios.

Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09 20:44:56 -07:00
Lee Schermerhorn
5c0c165490 mempolicy: fix dangling reference to tmpfs superblock mpol
My patch to "Factor out duplicate put/frees in mpol_shared_policy_init()
to a common return path"; and Dan Carpenter's fix thereto both left a
dangling reference to the incoming tmpfs superblock mempolicy structure.
A similar leak was introduced earlier when the nodemask was moved offstack
to the scratch area despite the note in the comment block regarding the
incoming ref.

Move the remaining 'put of the incoming "mpol" to the common exit path to
drop the reference.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: Dan Carpenter <error27@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.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>
2010-06-29 15:29:31 -07:00
Dan Carpenter
0cae3457b1 mempolicy: ERR_PTR dereference in mpol_shared_policy_init()
The original code called mpol_put(new) while "new" was an ERR_PTR.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-26 08:19:23 -07:00
Greg Thelen
6ec3a12712 mm: consider the entire user address space during node migration
Use mm->task_size instead of TASK_SIZE to ensure that the entire user
address space is migrated.  mm->task_size is independent of the calling
task context.  TASK SIZE may be dependant on the address space size of the
calling process.  Usage of TASK_SIZE can lead to partial address space
migration if the calling process was 32 bit and the migrating process was
64 bit.

Here is the test script used on 64 system with a 32 bit echo process:

  mount -t cgroup none /cgroup -o cpuset
  cd /cgroup

  mkdir 0
  echo 1 > 0/cpuset.cpus
  echo 0 > 0/cpuset.mems
  echo 1 > 0/cpuset.memory_migrate

  mkdir 1
  echo 1 > 1/cpuset.cpus
  echo 1 > 1/cpuset.mems
  echo 1 > 1/cpuset.memory_migrate

  echo $$ > 0/tasks
  64_bit_process &
  pid=$!

  echo $pid > 1/tasks   # This does not migrate all process pages without
                        # this patch.  If 64 bit echo is used or this patch is
                        # applied, then the full address space of $pid is
                        # migrated.

To check memory migration, I watched:
  grep MemUsed /sys/devices/system/node/node*/meminfo

Signed-off-by: Greg Thelen <gthelen@google.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:00 -07:00
Miao Xie
c0ff7453bb cpuset,mm: fix no node to alloc memory when changing cpuset's mems
Before applying this patch, cpuset updates task->mems_allowed and
mempolicy by setting all new bits in the nodemask first, and clearing all
old unallowed bits later.  But in the way, the allocator may find that
there is no node to alloc memory.

The reason is that cpuset rebinds the task's mempolicy, it cleans the
nodes which the allocater can alloc pages on, for example:

(mpol: mempolicy)
	task1			task1's mpol	task2
	alloc page		1
	  alloc on node0? NO	1
				1		change mems from 1 to 0
				1		rebind task1's mpol
				0-1		  set new bits
				0	  	  clear disallowed bits
	  alloc on node1? NO	0
	  ...
	can't alloc page
	  goto oom

This patch fixes this problem by expanding the nodes range first(set newly
allowed bits) and shrink it lazily(clear newly disallowed bits).  So we
use a variable to tell the write-side task that read-side task is reading
nodemask, and the write-side task clears newly disallowed nodes after
read-side task ends the current memory allocation.

[akpm@linux-foundation.org: fix spello]
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Miao Xie
708c1bbc9d mempolicy: restructure rebinding-mempolicy functions
Nick Piggin reported that the allocator may see an empty nodemask when
changing cpuset's mems[1].  It happens only on the kernel that do not do
atomic nodemask_t stores.  (MAX_NUMNODES > BITS_PER_LONG)

But I found that there is also a problem on the kernel that can do atomic
nodemask_t stores.  The problem is that the allocator can't find a node to
alloc page when changing cpuset's mems though there is a lot of free
memory.  The reason is like this:

(mpol: mempolicy)
	task1			task1's mpol	task2
	alloc page		1
	  alloc on node0? NO	1
				1		change mems from 1 to 0
				1		rebind task1's mpol
				0-1		  set new bits
				0	  	  clear disallowed bits
	  alloc on node1? NO	0
	  ...
	can't alloc page
	  goto oom

I can use the attached program reproduce it by the following step:

# mkdir /dev/cpuset
# mount -t cpuset cpuset /dev/cpuset
# mkdir /dev/cpuset/1
# echo `cat /dev/cpuset/cpus` > /dev/cpuset/1/cpus
# echo `cat /dev/cpuset/mems` > /dev/cpuset/1/mems
# echo $$ > /dev/cpuset/1/tasks
# numactl --membind=`cat /dev/cpuset/mems` ./cpuset_mem_hog <nr_tasks> &
   <nr_tasks> = max(nr_cpus - 1, 1)
# killall -s SIGUSR1 cpuset_mem_hog
# ./change_mems.sh

several hours later, oom will happen though there is a lot of free memory.

This patchset fixes this problem by expanding the nodes range first(set
newly allowed bits) and shrink it lazily(clear newly disallowed bits).  So
we use a variable to tell the write-side task that read-side task is
reading nodemask, and the write-side task clears newly disallowed nodes
after read-side task ends the current memory allocation.

This patch:

In order to fix no node to alloc memory, when we want to update mempolicy
and mems_allowed, we expand the set of nodes first (set all the newly
nodes) and shrink the set of nodes lazily(clean disallowed nodes), But the
mempolicy's rebind functions may breaks the expanding.

So we restructure the mempolicy's rebind functions and split the rebind
work to two steps, just like the update of cpuset's mems: The 1st step:
expand the set of the mempolicy's nodes.  The 2nd step: shrink the set of
the mempolicy's nodes.  It is used when there is no real lock to protect
the mempolicy in the read-side.  Otherwise we can do rebind work at once.

In order to implement it, we define

	enum mpol_rebind_step {
		MPOL_REBIND_ONCE,
		MPOL_REBIND_STEP1,
		MPOL_REBIND_STEP2,
		MPOL_REBIND_NSTEP,
	};

If the mempolicy needn't be updated by two steps, we can pass
MPOL_REBIND_ONCE to the rebind functions.  Or we can pass
MPOL_REBIND_STEP1 to do the first step of the rebind work and pass
MPOL_REBIND_STEP2 to do the second step work.

Besides that, it maybe long time between these two step and we have to
release the lock that protects mempolicy and mems_allowed.  If we hold the
lock once again, we must check whether the current mempolicy is under the
rebinding (the first step has been done) or not, because the task may
alloc a new mempolicy when we don't hold the lock.  So we defined the
following flag to identify it:

#define MPOL_F_REBINDING (1 << 2)

The new functions will be used in the next patch.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Lee Schermerhorn
15d77835ac mempolicy: factor mpol_shared_policy_init() return paths
Factor out duplicate put/frees in mpol_shared_policy_init() to a common
return path.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Lee Schermerhorn
345ace9c79 mempolicy: rename policy_types and cleanup initialization
Rename 'policy_types[]' to 'policy_modes[]' to better match the array
contents.

Use designated intializer syntax for policy_modes[].

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Lee Schermerhorn
b4652e8429 mempolicy: lose unnecessary loop variable in mpol_parse_str()
We don't really need the extra variable 'i' in mpol_parse_str().  The only
use is as the the loop variable.  Then, it's assigned to 'mode'.  Just use
mode, and loose the 'uninitialized_var()' macro.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Lee Schermerhorn
e17f74af35 mempolicy: don't call mpol_set_nodemask() when no_context
No need to call mpol_set_nodemask() when we have no context for the
mempolicy.  This can occur when we're parsing a tmpfs 'mpol' mount option.
 Just save the raw nodemask in the mempolicy's w.user_nodemask member for
use when a tmpfs/shmem file is created.  mpol_shared_policy_init() will
"contextualize" the policy for the new file based on the creating task's
context.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Bob Liu
1980050250 mempolicy: remove redundant check
Lee's patch "mempolicy: use MPOL_PREFERRED for system-wide default policy"
has made the MPOL_DEFAULT only used in the memory policy APIs.  So, no
need to check in __mpol_equal also.  Also get rid of mpol_match_intent()
and move its logic directly into __mpol_equal().

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Bob Liu
6eb27e1fdf mempolicy: remove case MPOL_INTERLEAVE from policy_zonelist()
In policy_zonelist() mode MPOL_INTERLEAVE shouldn't happen, so fall
through to BUG() instead of break to return.  I also fixed the comment.

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Bob Liu
6d556294d5 mempolicy: remove redundant code
1.  In funtion is_valid_nodemask(), varibable k will be inited to 0 in
   the following loop, needn't init to policy_zone anymore.

2. (MPOL_F_STATIC_NODES | MPOL_F_RELATIVE_NODES) has already defined
   to MPOL_MODE_FLAGS in mempolicy.h.

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
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>
2010-05-25 08:06:57 -07:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Lee Schermerhorn
c6b6ef8bb0 mempolicy: fix get_mempolicy() for relative and static nodes
Discovered while testing other mempolicy changes:

get_mempolicy() does not handle static/relative mode flags correctly.
Return the value that the user specified so that it can be restored
via set_mempolicy() if desired.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-24 16:31:22 -07:00
KOSAKI Motohiro
926f2ae04f tmpfs: cleanup mpol_parse_str()
mpol_parse_str() made lots 'err' variable related bug.  Because it is ugly
and reviewing unfriendly.

This patch simplifies it.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-24 16:31:21 -07:00
KOSAKI Motohiro
12821f5fb9 tmpfs: handle MPOL_LOCAL mount option properly
commit 71fe804b6d (mempolicy: use struct mempolicy pointer in
shmem_sb_info) added mpol=local mount option.  but its feature is broken
since it was born.  because such code always return 1 (i.e.  mount
failure).

This patch fixes it.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-24 16:31:21 -07:00
KOSAKI Motohiro
d69b2e63e9 tmpfs: mpol=bind:0 don't cause mount error.
Currently, following mount operation cause mount error.

% mount -t tmpfs -ompol=bind:0 none /tmp

Because commit 71fe804b6d (mempolicy: use struct mempolicy pointer in
shmem_sb_info) corrupted MPOL_BIND parse code.

This patch restore the needed one.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-24 16:31:21 -07:00
Ravikiran G Thirumalai
413b43deab tmpfs: fix oops on mounts with mpol=default
Fix an 'oops' when a tmpfs mount point is mounted with the mpol=default
mempolicy.

Upon remounting a tmpfs mount point with 'mpol=default' option, the mount
code crashed with a null pointer dereference.  The initial problem report
was on 2.6.27, but the problem exists in mainline 2.6.34-rc as well.  On
examining the code, we see that mpol_new returns NULL if default mempolicy
was requested.  This 'NULL' mempolicy is accessed to store the node mask
resulting in oops.

The following patch fixes it.

Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-24 16:31:21 -07:00
Linus Torvalds
4e3eaddd14 Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  locking: Make sparse work with inline spinlocks and rwlocks
  x86/mce: Fix RCU lockdep splats
  rcu: Increase RCU CPU stall timeouts if PROVE_RCU
  ftrace: Replace read_barrier_depends() with rcu_dereference_raw()
  rcu: Suppress RCU lockdep warnings during early boot
  rcu, ftrace: Fix RCU lockdep splat in ftrace_perf_buf_prepare()
  rcu: Suppress __mpol_dup() false positive from RCU lockdep
  rcu: Make rcu_read_lock_sched_held() handle !PREEMPT
  rcu: Add control variables to lockdep_rcu_dereference() diagnostics
  rcu, cgroup: Relax the check in task_subsys_state() as early boot is now handled by lockdep-RCU
  rcu: Use wrapper function instead of exporting tasklist_lock
  sched, rcu: Fix rcu_dereference() for RCU-lockdep
  rcu: Make task_subsys_state() RCU-lockdep checks handle boot-time use
  rcu: Fix holdoff for accelerated GPs for last non-dynticked CPU
  x86/gart: Unexport gart_iommu_aperture

Fix trivial conflicts in kernel/trace/ftrace.c
2010-03-13 14:43:01 -08:00
KOSAKI Motohiro
da0aa13894 mm/mempolicy.c: fix indentation of the comments of do_migrate_pages
Currently, do_migrate_pages() have very long comment and this is not
indent properly.  I often misunderstand it is function starting commnents
and confused it.

this patch fixes it.

note: this patch doesn't break 80 column rule. I guess original
      author intended this indentaion, but an accident corrupted it.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-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>
2010-03-06 11:26:25 -08:00
KOSAKI Motohiro
9d8cebd4bc mm: fix mbind vma merge problem
Strangely, current mbind() doesn't merge vma with neighbor vma although it's possible.
Unfortunately, many vma can reduce performance...

This patch fixes it.

    reproduced program
    ----------------------------------------------------------------
     #include <numaif.h>
     #include <numa.h>
     #include <sys/mman.h>
     #include <stdio.h>
     #include <unistd.h>
     #include <stdlib.h>
     #include <string.h>

    static unsigned long pagesize;

    int main(int argc, char** argv)
    {
    	void* addr;
    	int ch;
    	int node;
    	struct bitmask *nmask = numa_allocate_nodemask();
    	int err;
    	int node_set = 0;
    	char buf[128];

    	while ((ch = getopt(argc, argv, "n:")) != -1){
    		switch (ch){
    		case 'n':
    			node = strtol(optarg, NULL, 0);
    			numa_bitmask_setbit(nmask, node);
    			node_set = 1;
    			break;
    		default:
    			;
    		}
    	}
    	argc -= optind;
    	argv += optind;

    	if (!node_set)
    		numa_bitmask_setbit(nmask, 0);

    	pagesize = getpagesize();

    	addr = mmap(NULL, pagesize*3, PROT_READ|PROT_WRITE,
    		    MAP_ANON|MAP_PRIVATE, 0, 0);
    	if (addr == MAP_FAILED)
    		perror("mmap "), exit(1);

    	fprintf(stderr, "pid = %d \n" "addr = %p\n", getpid(), addr);

    	/* make page populate */
    	memset(addr, 0, pagesize*3);

    	/* first mbind */
    	err = mbind(addr+pagesize, pagesize, MPOL_BIND, nmask->maskp,
    		    nmask->size, MPOL_MF_MOVE_ALL);
    	if (err)
    		error("mbind1 ");

    	/* second mbind */
    	err = mbind(addr, pagesize*3, MPOL_DEFAULT, NULL, 0, 0);
    	if (err)
    		error("mbind2 ");

    	sprintf(buf, "cat /proc/%d/maps", getpid());
    	system(buf);

    	return 0;
    }
    ----------------------------------------------------------------

result without this patch

	addr = 0x7fe26ef09000
	[snip]
	7fe26ef09000-7fe26ef0a000 rw-p 00000000 00:00 0
	7fe26ef0a000-7fe26ef0b000 rw-p 00000000 00:00 0
	7fe26ef0b000-7fe26ef0c000 rw-p 00000000 00:00 0
	7fe26ef0c000-7fe26ef0d000 rw-p 00000000 00:00 0

	=> 0x7fe26ef09000-0x7fe26ef0c000 have three vmas.

result with this patch

	addr = 0x7fc9ebc76000
	[snip]
	7fc9ebc76000-7fc9ebc7a000 rw-p 00000000 00:00 0
	7fffbe690000-7fffbe6a5000 rw-p 00000000	00:00 0	[stack]

	=> 0x7fc9ebc76000-0x7fc9ebc7a000 have only one vma.

[minchan.kim@gmail.com: fix file offset passed to vma_merge()]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06 11:26:25 -08:00
Paul E. McKenney
99ee4ca746 rcu: Suppress __mpol_dup() false positive from RCU lockdep
Common code is used during task creation and after the task has
started running.  RCU protection is not needed during task
creation because no other CPU has access to the
under-construction task.  Provide the RCU protection anyway to
suppress the false positive, as there does not appear to be a
good way for the common code to recognize that the task is only
accessible to the CPU creating it.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1267667418-32233-2-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-04 12:07:34 +01:00
Hugh Dickins
62b61f611e ksm: memory hotremove migration only
The previous patch enables page migration of ksm pages, but that soon gets
into trouble: not surprising, since we're using the ksm page lock to lock
operations on its stable_node, but page migration switches the page whose
lock is to be used for that.  Another layer of locking would fix it, but
do we need that yet?

Do we actually need page migration of ksm pages?  Yes, memory hotremove
needs to offline sections of memory: and since we stopped allocating ksm
pages with GFP_HIGHUSER, they will tend to be GFP_HIGHUSER_MOVABLE
candidates for migration.

But KSM is currently unconscious of NUMA issues, happily merging pages
from different NUMA nodes: at present the rule must be, not to use
MADV_MERGEABLE where you care about NUMA.  So no, NUMA page migration of
ksm pages does not make sense yet.

So, to complete support for ksm swapping we need to make hotremove safe.
ksm_memory_callback() take ksm_thread_mutex when MEM_GOING_OFFLINE and
release it when MEM_OFFLINE or MEM_CANCEL_OFFLINE.  But if mapped pages
are freed before migration reaches them, stable_nodes may be left still
pointing to struct pages which have been removed from the system: the
stable_node needs to identify a page by pfn rather than page pointer, then
it can safely prune them when MEM_OFFLINE.

And make NUMA migration skip PageKsm pages where it skips PageReserved.
But it's only when we reach unmap_and_move() that the page lock is taken
and we can be sure that raised pagecount has prevented a PageAnon from
being upgraded: so add offlining arg to migrate_pages(), to migrate ksm
page when offlining (has sufficient locking) but reject it otherwise.

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Izik Eidus <ieidus@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Chris Wright <chrisw@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:20 -08:00
Lee Schermerhorn
06808b0827 hugetlb: derive huge pages nodes allowed from task mempolicy
This patch derives a "nodes_allowed" node mask from the numa mempolicy of
the task modifying the number of persistent huge pages to control the
allocation, freeing and adjusting of surplus huge pages when the pool page
count is modified via the new sysctl or sysfs attribute
"nr_hugepages_mempolicy".  The nodes_allowed mask is derived as follows:

* For "default" [NULL] task mempolicy, a NULL nodemask_t pointer
  is produced.  This will cause the hugetlb subsystem to use
  node_online_map as the "nodes_allowed".  This preserves the
  behavior before this patch.
* For "preferred" mempolicy, including explicit local allocation,
  a nodemask with the single preferred node will be produced.
  "local" policy will NOT track any internode migrations of the
  task adjusting nr_hugepages.
* For "bind" and "interleave" policy, the mempolicy's nodemask
  will be used.
* Other than to inform the construction of the nodes_allowed node
  mask, the actual mempolicy mode is ignored.  That is, all modes
  behave like interleave over the resulting nodes_allowed mask
  with no "fallback".

See the updated documentation [next patch] for more information
about the implications of this patch.

Examples:

Starting with:

	Node 0 HugePages_Total:     0
	Node 1 HugePages_Total:     0
	Node 2 HugePages_Total:     0
	Node 3 HugePages_Total:     0

Default behavior [with or without this patch] balances persistent
hugepage allocation across nodes [with sufficient contiguous memory]:

	sysctl vm.nr_hugepages[_mempolicy]=32

yields:

	Node 0 HugePages_Total:     8
	Node 1 HugePages_Total:     8
	Node 2 HugePages_Total:     8
	Node 3 HugePages_Total:     8

Of course, we only have nr_hugepages_mempolicy with the patch,
but with default mempolicy, nr_hugepages_mempolicy behaves the
same as nr_hugepages.

Applying mempolicy--e.g., with numactl [using '-m' a.k.a.
'--membind' because it allows multiple nodes to be specified
and it's easy to type]--we can allocate huge pages on
individual nodes or sets of nodes.  So, starting from the
condition above, with 8 huge pages per node, add 8 more to
node 2 using:

	numactl -m 2 sysctl vm.nr_hugepages_mempolicy=40

This yields:

	Node 0 HugePages_Total:     8
	Node 1 HugePages_Total:     8
	Node 2 HugePages_Total:    16
	Node 3 HugePages_Total:     8

The incremental 8 huge pages were restricted to node 2 by the
specified mempolicy.

Similarly, we can use mempolicy to free persistent huge pages
from specified nodes:

	numactl -m 0,1 sysctl vm.nr_hugepages_mempolicy=32

yields:

	Node 0 HugePages_Total:     4
	Node 1 HugePages_Total:     4
	Node 2 HugePages_Total:    16
	Node 3 HugePages_Total:     8

The 8 huge pages freed were balanced over nodes 0 and 1.

[rientjes@google.com: accomodate reworked NODEMASK_ALLOC]
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Andi Kleen <andi@firstfloor.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Eric Whitney <eric.whitney@hp.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>
2009-12-15 08:53:12 -08:00
KOSAKI Motohiro
6d9c285a63 mm: move inc_zone_page_state(NR_ISOLATED) to just isolated place
Christoph pointed out inc_zone_page_state(NR_ISOLATED) should be placed
in right after isolate_page().

This patch does it.

Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
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>
2009-12-15 08:53:12 -08:00
KOSAKI Motohiro
b05ca7385a do_mbind(): fix memory leak
If migrate_prep is failed, new variable is leaked.  This patch fixes it.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-29 07:39:29 -07:00