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  1. 09 Jul, 2011 5 commits
    • Shaohua Li's avatar
      mm: __tlb_remove_page() check the correct batch · 0b43c3aa
      Shaohua Li authored 
      __tlb_remove_page() switches to a new batch page, but still checks space
in the old batch.  This check always fails, and causes a forced tlb flush.
Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0b43c3aa
    • Mel Gorman's avatar
      mm: vmscan: only read new_classzone_idx from pgdat when reclaiming successfully · 215ddd66
      Mel Gorman authored 
      During allocator-intensive workloads, kswapd will be woken frequently
causing free memory to oscillate between the high and min watermark.  This
is expected behaviour.  Unfortunately, if the highest zone is small, a
problem occurs.

When balance_pgdat() returns, it may be at a lower classzone_idx than it
started because the highest zone was unreclaimable.  Before checking if it
should go to sleep though, it checks pgdat->classzone_idx which when there
is no other activity will be MAX_NR_ZONES-1.  It interprets this as it has
been woken up while reclaiming, skips scheduling and reclaims again.  As
there is no useful reclaim work to do, it enters into a loop of shrinking
slab consuming loads of CPU until the highest zone becomes reclaimable for
a long period of time.

There are two problems here.  1) If the returned classzone or order is
lower, it'll continue reclaiming without scheduling.  2) if the highest
zone was marked unreclaimable but balance_pgdat() returns immediately at
DEF_PRIORITY, the new lower classzone is not communicated back to kswapd()
for sleeping.

This patch does two things that are related.  If the end_zone is
unreclaimable, this information is communicated back.  Second, if the
classzone or order was reduced due to failing to reclaim, new information
is not read from pgdat and instead an attempt is made to go to sleep.  Due
to this, it is also necessary that pgdat->classzone_idx be initialised
each time to pgdat->nr_zones - 1 to avoid re-reads being interpreted as
wakeups.
Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
Reported-by: default avatarPádraig Brady <P@draigBrady.com>
Tested-by: default avatarPádraig Brady <P@draigBrady.com>
Tested-by: default avatarAndrew Lutomirski <luto@mit.edu>
Acked-by: default avatarRik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      215ddd66
    • Mel Gorman's avatar
      mm: vmscan: evaluate the watermarks against the correct classzone · da175d06
      Mel Gorman authored 
      When deciding if kswapd is sleeping prematurely, the classzone is taken
into account but this is different to what balance_pgdat() and the
allocator are doing.  Specifically, the DMA zone will be checked based on
the classzone used when waking kswapd which could be for a GFP_KERNEL or
GFP_HIGHMEM request.  The lowmem reserve limit kicks in, the watermark is
not met and kswapd thinks it's sleeping prematurely keeping kswapd awake in
error.
Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
Reported-by: default avatarPádraig Brady <P@draigBrady.com>
Tested-by: default avatarPádraig Brady <P@draigBrady.com>
Tested-by: default avatarAndrew Lutomirski <luto@mit.edu>
Acked-by: default avatarRik van Riel <riel@redhat.com>
Reviewed-by: default avatarMinchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      da175d06
    • Mel Gorman's avatar
      mm: vmscan: do not apply pressure to slab if we are not applying pressure to zone · d7868dae
      Mel Gorman authored 
      During allocator-intensive workloads, kswapd will be woken frequently
causing free memory to oscillate between the high and min watermark.  This
is expected behaviour.

When kswapd applies pressure to zones during node balancing, it checks if
the zone is above a high+balance_gap threshold.  If it is, it does not
apply pressure but it unconditionally shrinks slab on a global basis which
is excessive.  In the event kswapd is being kept awake due to a high small
unreclaimable zone, it skips zone shrinking but still calls shrink_slab().

Once pressure has been applied, the check for zone being unreclaimable is
being made before the check is made if all_unreclaimable should be set.
This miss of unreclaimable can cause has_under_min_watermark_zone to be
set due to an unreclaimable zone preventing kswapd backing off on
congestion_wait().
Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
Reported-by: default avatarPádraig Brady <P@draigBrady.com>
Tested-by: default avatarPádraig Brady <P@draigBrady.com>
Tested-by: default avatarAndrew Lutomirski <luto@mit.edu>
Acked-by: default avatarRik van Riel <riel@redhat.com>
Reviewed-by: default avatarMinchan Kim <minchan.kim@gmail.com>
Reviewed-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d7868dae
    • Mel Gorman's avatar
      mm: vmscan: correct check for kswapd sleeping in sleeping_prematurely · 08951e54
      Mel Gorman authored 
      During allocator-intensive workloads, kswapd will be woken frequently
causing free memory to oscillate between the high and min watermark.  This
is expected behaviour.  Unfortunately, if the highest zone is small, a
problem occurs.

This seems to happen most with recent sandybridge laptops but it's
probably a co-incidence as some of these laptops just happen to have a
small Normal zone.  The reproduction case is almost always during copying
large files that kswapd pegs at 100% CPU until the file is deleted or
cache is dropped.

The problem is mostly down to sleeping_prematurely() keeping kswapd awake
when the highest zone is small and unreclaimable and compounded by the
fact we shrink slabs even when not shrinking zones causing a lot of time
to be spent in shrinkers and a lot of memory to be reclaimed.

Patch 1 corrects sleeping_prematurely to check the zones matching
	the classzone_idx instead of all zones.

Patch 2 avoids shrinking slab when we are not shrinking a zone.

Patch 3 notes that sleeping_prematurely is checking lower zones against
	a high classzone which is not what allocators or balance_pgdat()
	is doing leading to an artifical belief that kswapd should be
	still awake.

Patch 4 notes that when balance_pgdat() gives up on a high zone that the
	decision is not communicated to sleeping_prematurely()

This problem affects 2.6.38.8 for certain and is expected to affect 2.6.39
and 3.0-rc4 as well.  If accepted, they need to go to -stable to be picked
up by distros and this series is against 3.0-rc4.  I've cc'd people that
reported similar problems recently to see if they still suffer from the
problem and if this fixes it.

This patch: correct the check for kswapd sleeping in sleeping_prematurely()

During allocator-intensive workloads, kswapd will be woken frequently
causing free memory to oscillate between the high and min watermark.  This
is expected behaviour.

A problem occurs if the highest zone is small.  balance_pgdat() only
considers unreclaimable zones when priority is DEF_PRIORITY but
sleeping_prematurely considers all zones.  It's possible for this sequence
to occur

  1. kswapd wakes up and enters balance_pgdat()
  2. At DEF_PRIORITY, marks highest zone unreclaimable
  3. At DEF_PRIORITY-1, ignores highest zone setting end_zone
  4. At DEF_PRIORITY-1, calls shrink_slab freeing memory from
        highest zone, clearing all_unreclaimable. Highest zone
        is still unbalanced
  5. kswapd returns and calls sleeping_prematurely
  6. sleeping_prematurely looks at *all* zones, not just the ones
     being considered by balance_pgdat. The highest small zone
     has all_unreclaimable cleared but the zone is not
     balanced. all_zones_ok is false so kswapd stays awake

This patch corrects the behaviour of sleeping_prematurely to check the
zones balance_pgdat() checked.
Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
Reported-by: default avatarPádraig Brady <P@draigBrady.com>
Tested-by: default avatarPádraig Brady <P@draigBrady.com>
Tested-by: default avatarAndrew Lutomirski <luto@mit.edu>
Acked-by: default avatarRik van Riel <riel@redhat.com>
Reviewed-by: default avatarMinchan Kim <minchan.kim@gmail.com>
Reviewed-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      08951e54
  3. 08 Jul, 2011 5 commits
  5. 07 Jul, 2011 21 commits
  7. 06 Jul, 2011 9 commits
    • Dave Chinner's avatar
      xfs: unpin stale inodes directly in IOP_COMMITTED · 1316d4da
      Dave Chinner authored 
      When inodes are marked stale in a transaction, they are treated
specially when the inode log item is being inserted into the AIL.
It tries to avoid moving the log item forward in the AIL due to a
race condition with the writing the underlying buffer back to disk.
The was "fixed" in commit de25c181 ("xfs: avoid moving stale inodes
in the AIL").

To avoid moving the item forward, we return a LSN smaller than the
commit_lsn of the completing transaction, thereby trying to trick
the commit code into not moving the inode forward at all. I'm not
sure this ever worked as intended - it assumes the inode is already
in the AIL, but I don't think the returned LSN would have been small
enough to prevent moving the inode. It appears that the reason it
worked is that the lower LSN of the inodes meant they were inserted
into the AIL and flushed before the inode buffer (which was moved to
the commit_lsn of the transaction).

The big problem is that with delayed logging, the returning of the
different LSN means insertion takes the slow, non-bulk path.  Worse
yet is that insertion is to a position -before- the commit_lsn so it
is doing a AIL traversal on every insertion, and has to walk over
all the items that have already been inserted into the AIL. It's
expensive.

To compound the matter further, with delayed logging inodes are
likely to go from clean to stale in a single checkpoint, which means
they aren't even in the AIL at all when we come across them at AIL
insertion time. Hence these were all getting inserted into the AIL
when they simply do not need to be as inodes marked XFS_ISTALE are
never written back.

Transactional/recovery integrity is maintained in this case by the
other items in the unlink transaction that were modified (e.g. the
AGI btree blocks) and committed in the same checkpoint.

So to fix this, simply unpin the stale inodes directly in
xfs_inode_item_committed() and return -1 to indicate that the AIL
insertion code does not need to do any further processing of these
inodes.
Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAlex Elder <aelder@sgi.com>
      1316d4da
    • Andrea Righi's avatar
      Documentation: fix cgroup blkio throttle filenames · 9b61fc4c
      Andrea Righi authored 
      All the blkio.throttle.* file names are incorrectly reported without
".throttle" in the documentation. Fix it.
Signed-off-by: default avatarAndrea Righi <andrea@betterlinux.com>
Signed-off-by: default avatarRandy Dunlap <randy.dunlap@oracle.com>
Acked-by: default avatarVivek Goyal <vgoyal@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9b61fc4c
    • Jesper Juhl's avatar
      Documentation: update CodingStyle memory allocators · 316b3799
      Jesper Juhl authored 
      The list of available general purpose memory allocators in
Documentation/CodingStyle chapter 14 is incomplete. This patch adds
the missing vzalloc() to the list.
Signed-off-by: default avatarJesper Juhl <jj@chaosbits.net>
Signed-off-by: default avatarRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      316b3799
    • Randy Dunlap's avatar
      MAINTAINERS: move kernel-doc patches location · 0dcb6d73
      Randy Dunlap authored 
      Move location of quilt series for kernel-doc patches.
Signed-off-by: default avatarRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0dcb6d73
    • Linus Torvalds's avatar
      Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6 · de3796e7
      Linus Torvalds authored 
      * 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: (46 commits)
  [media] rc: call input_sync after scancode reports
  [media] imon: allow either proto on unknown 0xffdc
  [media] imon: auto-config ffdc 7e device
  [media] saa7134: fix raw IR timeout value
  [media] rc: fix ghost keypresses with certain hw
  [media] [staging] lirc_serial: allocate irq at init time
  [media] lirc_zilog: fix spinning rx thread
  [media] keymaps: fix table for pinnacle pctv hd devices
  [media] ite-cir: 8709 needs to use pnp resource 2
  [media] V4L: mx1-camera: fix uninitialized variable
  [media] omap_vout: Added check in reqbuf & mmap for buf_size allocation
  [media] OMAP_VOUT: Change hardcoded device node number to -1
  [media] OMAP_VOUTLIB: Fix wrong resizer calculation
  [media] uvcvideo: Disable the queue when failing to start
  [media] uvcvideo: Remove buffers from the queues when freeing
  [media] uvcvideo: Ignore entities for terminals with no supported format
  [media] v4l: Don't access media entity after is has been destroyed
  [media] media: omap3isp: fix a potential NULL deref
  [media] media: vb2: fix allocation failure check
  [media] media: vb2: reset queued_count value during queue reinitialization
  ...

Fix up trivial conflict in MAINTAINERS as per Mauro
      de3796e7
    • Davidlohr Bueso's avatar
      FDPIC: Fix memory leak · bcb65a79
      Davidlohr Bueso authored 
      The shdr4extnum variable isn't being freed in the cleanup process of
elf_fdpic_core_dump().
Signed-off-by: default avatarDavidlohr Bueso <dave@gnu.org>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      bcb65a79
    • Rafael J. Wysocki's avatar
      PM / Hibernate: Fix free_unnecessary_pages() · 4d4cf23c
      Rafael J. Wysocki authored 
      There is a bug in free_unnecessary_pages() that causes it to
attempt to free too many pages in some cases, which triggers the
BUG_ON() in memory_bm_clear_bit() for copy_bm.  Namely, if
count_data_pages() is initially greater than alloc_normal, we get
to_free_normal equal to 0 and "save" greater from 0.  In that case,
if the sum of "save" and count_highmem_pages() is greater than
alloc_highmem, we subtract a positive number from to_free_normal.
Hence, since to_free_normal was 0 before the subtraction and is
an unsigned int, the result is converted to a huge positive number
that is used as the number of pages to free.

Fix this bug by checking if to_free_normal is actually greater
than or equal to the number we're going to subtract from it.
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Reported-and-tested-by: default avatarMatthew Garrett <mjg@redhat.com>
Cc: stable@kernel.org
      4d4cf23c
    • Ram Pai's avatar
      resource: ability to resize an allocated resource · 23c570a6
      Ram Pai authored 
      Provides the ability to resize a resource that is already allocated.
This functionality is put in place to support reallocation needs of
pci resources.
Signed-off-by: default avatarRam Pai <linuxram@us.ibm.com>
Acked-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      23c570a6
    • Miklos Szeredi's avatar
      fs: fix lock initialization · a51cb91d
      Miklos Szeredi authored 
      locks_alloc_lock() assumed that the allocated struct file_lock is
already initialized to zero members.  This is only true for the first
allocation of the structure, after reuse some of the members will have
random values.

This will for example result in passing random fl_start values to
userspace in fuse for FL_FLOCK locks, which is an information leak at
best.

Fix by reinitializing those members which may be non-zero after freeing.
Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
CC: stable@kernel.org
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a51cb91d
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