linux-stable.git/mm/migrate.c, branch v3.2

mm/migrate.c: pair unlock_page() and lock_page() when migrating huge pages

2011-12-09T15:50:28+00:00

Avoid unlocking and unlocked page if we failed to lock it.

Signed-off-by: Hillf Danton 
Cc: Naoya Horiguchi 
Cc: Andrea Arcangeli 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

2011-11-07T03:44:47+00:00

* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
  Revert "tracing: Include module.h in define_trace.h"
  irq: don't put module.h into irq.h for tracking irqgen modules.
  bluetooth: macroize two small inlines to avoid module.h
  ip_vs.h: fix implicit use of module_get/module_put from module.h
  nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
  include: replace linux/module.h with "struct module" wherever possible
  include: convert various register fcns to macros to avoid include chaining
  crypto.h: remove unused crypto_tfm_alg_modname() inline
  uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
  pm_runtime.h: explicitly requires notifier.h
  linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
  miscdevice.h: fix up implicit use of lists and types
  stop_machine.h: fix implicit use of smp.h for smp_processor_id
  of: fix implicit use of errno.h in include/linux/of.h
  of_platform.h: delete needless include 
  acpi: remove module.h include from platform/aclinux.h
  miscdevice.h: delete unnecessary inclusion of module.h
  device_cgroup.h: delete needless include 
  net: sch_generic remove redundant use of 
  net: inet_timewait_sock doesnt need 
  ...

Fix up trivial conflicts (other header files, and  removal of the ab3550 mfd driver) in
 - drivers/media/dvb/frontends/dibx000_common.c
 - drivers/media/video/{mt9m111.c,ov6650.c}
 - drivers/mfd/ab3550-core.c
 - include/linux/dmaengine.h

mm: migration: clean up unmap_and_move()

2011-11-01T00:30:45+00:00

unmap_and_move() is one a big messy function.  Clean it up.

Signed-off-by: Minchan Kim 
Reviewed-by: KOSAKI Motohiro 
Cc: Johannes Weiner 
Cc: KAMEZAWA Hiroyuki 
Cc: Mel Gorman 
Cc: Rik van Riel 
Cc: Michal Hocko 
Cc: Andrea Arcangeli 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: Map most files to use export.h instead of module.h

2011-10-31T13:20:12+00:00

The files changed within are only using the EXPORT_SYMBOL
macro variants.  They are not using core modular infrastructure
and hence don't need module.h but only the export.h header.

Signed-off-by: Paul Gortmaker

mm: fix race between mremap and removing migration entry

2011-10-20T06:42:58+00:00

I don't usually pay much attention to the stale "? " addresses in
stack backtraces, but this lucky report from Pawel Sikora hints that
mremap's move_ptes() has inadequate locking against page migration.

 3.0 BUG_ON(!PageLocked(p)) in migration_entry_to_page():
 kernel BUG at include/linux/swapops.h:105!
 RIP: 0010:[]  []
                       migration_entry_wait+0x156/0x160
  [] handle_pte_fault+0xae1/0xaf0
  [] ? __pte_alloc+0x42/0x120
  [] ? do_huge_pmd_anonymous_page+0xab/0x310
  [] handle_mm_fault+0x181/0x310
  [] ? vma_adjust+0x537/0x570
  [] do_page_fault+0x11d/0x4e0
  [] ? do_mremap+0x2d5/0x570
  [] page_fault+0x1f/0x30

mremap's down_write of mmap_sem, together with i_mmap_mutex or lock,
and pagetable locks, were good enough before page migration (with its
requirement that every migration entry be found) came in, and enough
while migration always held mmap_sem; but not enough nowadays, when
there's memory hotremove and compaction.

The danger is that move_ptes() lets a migration entry dodge around
behind remove_migration_pte()'s back, so it's in the old location when
looking at the new, then in the new location when looking at the old.

Either mremap's move_ptes() must additionally take anon_vma lock(), or
migration's remove_migration_pte() must stop peeking for is_swap_entry()
before it takes pagetable lock.

Consensus chooses the latter: we prefer to add overhead to migration
than to mremapping, which gets used by JVMs and by exec stack setup.

Reported-and-tested-by: Paweł Sikora 
Signed-off-by: Hugh Dickins 
Acked-by: Andrea Arcangeli 
Acked-by: Mel Gorman 
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds

migrate: don't account swapcache as shmem

2011-06-16T22:01:24+00:00

swapcache will reach the below code path in migrate_page_move_mapping,
and swapcache is accounted as NR_FILE_PAGES but it's not accounted as
NR_SHMEM.

Hugh pointed out we must use PageSwapCache instead of comparing
mapping to &swapper_space, to avoid build failure with CONFIG_SWAP=n.

Signed-off-by: Andrea Arcangeli 
Acked-by: Hugh Dickins 
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds

mm: use refcounts for page_lock_anon_vma()

2011-05-25T15:39:19+00:00

Convert page_lock_anon_vma() over to use refcounts.  This is done to
prepare for the conversion of anon_vma from spinlock to mutex.

Sadly this inceases the cost of page_lock_anon_vma() from one to two
atomics, a follow up patch addresses this, lets keep that simple for now.

Signed-off-by: Peter Zijlstra 
Reviewed-by: KAMEZAWA Hiroyuki 
Reviewed-by: KOSAKI Motohiro 
Acked-by: Hugh Dickins 
Cc: Benjamin Herrenschmidt 
Cc: David Miller 
Cc: Martin Schwidefsky 
Cc: Russell King 
Cc: Paul Mundt 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Tony Luck 
Cc: Mel Gorman 
Cc: Nick Piggin 
Cc: Namhyung Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Fix common misspellings

2011-03-31T14:26:23+00:00

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi

memcg: fix ugly initialization of return value is in caller

2011-03-24T02:46:22+00:00

Remove initialization of vaiable in caller of memory cgroup function.
Actually, it's return value of memcg function but it's initialized in
caller.

Some memory cgroup uses following style to bring the result of start
function to the end function for avoiding races.

   mem_cgroup_start_A(&(*ptr))
   /* Something very complicated can happen here. */
   mem_cgroup_end_A(*ptr)

In some calls, *ptr should be initialized to NULL be caller.  But it's
ugly.  This patch fixes that *ptr is initialized by _start function.

Signed-off-by: KAMEZAWA Hiroyuki 
Acked-by: Johannes Weiner 
Acked-by: Daisuke Nishimura 
Cc: Balbir Singh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: compaction: Use async migration for __GFP_NO_KSWAPD and enforce no writeback

2011-03-23T00:44:05+00:00

__GFP_NO_KSWAPD allocations are usually very expensive and not mandatory
to succeed as they have graceful fallback.  Waiting for I/O in those,
tends to be overkill in terms of latencies, so we can reduce their latency
by disabling sync migrate.

Unfortunately, even with async migration it's still possible for the
process to be blocked waiting for a request slot (e.g.  get_request_wait
in the block layer) when ->writepage is called.  To prevent
__GFP_NO_KSWAPD blocking, this patch prevents ->writepage being called on
dirty page cache for asynchronous migration.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=31142

[mel@csn.ul.ie: Avoid writebacks for NFS, retry locked pages, use bool]
Signed-off-by: Andrea Arcangeli 
Signed-off-by: Mel Gorman 
Cc: Arthur Marsh 
Cc: Clemens Ladisch 
Cc: Johannes Weiner 
Cc: KAMEZAWA Hiroyuki 
Cc: Minchan Kim 
Reported-by: Alex Villacis Lasso 
Tested-by: Alex Villacis Lasso 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds