linux/fs/xfs/linux-2.6
Dave Chinner 228d62dd3f xfs: ensure reclaim cursor is reset correctly at end of AG
On a 32 bit highmem PowerPC machine, the XFS inode cache was growing
without bound and exhausting low memory causing the OOM killer to be
triggered. After some effort, the problem was reproduced on a 32 bit
x86 highmem machine.

The problem is that the per-ag inode reclaim index cursor was not
getting reset to the start of the AG if the radix tree tag lookup
found no more reclaimable inodes. Hence every further reclaim
attempt started at the same index beyond where any reclaimable
inodes lay, and no further background reclaim ever occurred from the
AG.

Without background inode reclaim the VM driven cache shrinker
simply cannot keep up with cache growth, and OOM is the result.

While the change that exposed the problem was the conversion of the
inode reclaim to use work queues for background reclaim, it was not
the cause of the bug. The bug was introduced when the cursor code
was added, just waiting for some weird configuration to strike....

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Tested-By: Christian Kujau <lists@nerdbynature.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>

(cherry picked from commit b223221956)
2011-05-09 18:35:03 -05:00
..
kmem.c
kmem.h
mrlock.h
time.h
xfs_acl.c
xfs_aops.c Fix common misspellings 2011-03-31 11:26:23 -03:00
xfs_aops.h
xfs_buf.c Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs 2011-04-11 15:48:57 -07:00
xfs_buf.h xfs: stop using the page cache to back the buffer cache 2011-03-26 09:16:45 +11:00
xfs_discard.c
xfs_discard.h
xfs_export.c exportfs: Return the minimum required handle size 2011-03-14 09:15:28 -04:00
xfs_export.h
xfs_file.c Fix common misspellings 2011-03-31 11:26:23 -03:00
xfs_fs_subr.c
xfs_globals.c
xfs_ioctl.c xfs: preallocation transactions do not need to be synchronous 2011-03-26 09:13:08 +11:00
xfs_ioctl.h
xfs_ioctl32.c
xfs_ioctl32.h
xfs_iops.c Fix common misspellings 2011-03-31 11:26:23 -03:00
xfs_iops.h
xfs_linux.h
xfs_message.c xfs: fix duplicate message output 2011-04-20 11:36:49 -05:00
xfs_message.h xfs: fix xfs_debug warnings 2011-04-08 08:09:24 -05:00
xfs_quotaops.c
xfs_stats.c
xfs_stats.h
xfs_super.c xfs_destroy_workqueues() should not be tagged with__exit 2011-04-11 15:47:20 -07:00
xfs_super.h
xfs_sync.c xfs: ensure reclaim cursor is reset correctly at end of AG 2011-05-09 18:35:03 -05:00
xfs_sync.h xfs: introduce a xfssyncd workqueue 2011-04-08 12:45:07 +10:00
xfs_sysctl.c
xfs_sysctl.h
xfs_trace.c
xfs_trace.h
xfs_vnode.h
xfs_xattr.c