kernel-ark/mm
Nishanth Aravamudan 11320d17ce hugetlb: fix potential livelock in return_unused_surplus_hugepages()
Running the counters testcase from libhugetlbfs results in on 2.6.25-rc5
and 2.6.25-rc5-mm1:

    BUG: soft lockup - CPU#3 stuck for 61s! [counters:10531]
    NIP: c0000000000d1f3c LR: c0000000000d1f2c CTR: c0000000001b5088
    REGS: c000005db12cb360 TRAP: 0901   Not tainted  (2.6.25-rc5-autokern1)
    MSR: 8000000000009032 <EE,ME,IR,DR>  CR: 48008448  XER: 20000000
    TASK = c000005dbf3d6000[10531] 'counters' THREAD: c000005db12c8000 CPU: 3
    GPR00: 0000000000000004 c000005db12cb5e0 c000000000879228 0000000000000004
    GPR04: 0000000000000010 0000000000000000 0000000000200200 0000000000100100
    GPR08: c0000000008aba10 000000000000ffff 0000000000000004 0000000000000000
    GPR12: 0000000028000442 c000000000770080
    NIP [c0000000000d1f3c] .return_unused_surplus_pages+0x84/0x18c
    LR [c0000000000d1f2c] .return_unused_surplus_pages+0x74/0x18c
    Call Trace:
    [c000005db12cb5e0] [c000005db12cb670] 0xc000005db12cb670 (unreliable)
    [c000005db12cb670] [c0000000000d24c4] .hugetlb_acct_memory+0x2e0/0x354
    [c000005db12cb740] [c0000000001b5048] .truncate_hugepages+0x1d4/0x214
    [c000005db12cb890] [c0000000001b50a4] .hugetlbfs_delete_inode+0x1c/0x3c
    [c000005db12cb920] [c000000000103fd8] .generic_delete_inode+0xf8/0x1c0
    [c000005db12cb9b0] [c0000000001b5100] .hugetlbfs_drop_inode+0x3c/0x24c
    [c000005db12cba50] [c00000000010287c] .iput+0xdc/0xf8
    [c000005db12cbad0] [c0000000000fee54] .dentry_iput+0x12c/0x194
    [c000005db12cbb60] [c0000000000ff050] .d_kill+0x6c/0xa4
    [c000005db12cbbf0] [c0000000000ffb74] .dput+0x18c/0x1b0
    [c000005db12cbc70] [c0000000000e9e98] .__fput+0x1a4/0x1e8
    [c000005db12cbd10] [c0000000000e61ec] .filp_close+0xb8/0xe0
    [c000005db12cbda0] [c0000000000e62d0] .sys_close+0xbc/0x134
    [c000005db12cbe30] [c00000000000872c] syscall_exit+0x0/0x40
    Instruction dump:
    ebbe8038 38800010 e8bf0002 3bbd0008 7fa3eb78 38a50001 7ca507b4 4818df25
    60000000 38800010 38a00000 7c601b78 <7fa3eb78> 2f800010 409d0008 38000010

This was tracked down to a potential livelock in
return_unused_surplus_hugepages().  In the case where we have surplus
pages on some node, but no free pages on the same node, we may never
break out of the loop. To avoid this livelock, terminate the search if
we iterate a number of times equal to the number of online nodes without
freeing a page.

Thanks to Andy Whitcroft and Adam Litke for helping with debugging and
the patch.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-26 15:01:33 -07:00
..
allocpercpu.c
backing-dev.c
bootmem.c mm: fix boundary checking in free_bootmem_core 2008-03-24 19:22:19 -07:00
bounce.c
dmapool.c
fadvise.c
filemap_xip.c
filemap.c mm: fix various kernel-doc comments 2008-03-19 18:53:35 -07:00
fremap.c mm: fix various kernel-doc comments 2008-03-19 18:53:35 -07:00
highmem.c mm: highmem kernel-doc additions 2008-03-19 18:53:35 -07:00
hugetlb.c hugetlb: fix potential livelock in return_unused_surplus_hugepages() 2008-03-26 15:01:33 -07:00
internal.h
Kconfig
madvise.c
Makefile
memcontrol.c memcgroup: fix check for thread being a group leader in memcgroup 2008-03-19 18:53:35 -07:00
memory_hotplug.c
memory.c
mempolicy.c
mempool.c
migrate.c
mincore.c
mlock.c
mmap.c
mmzone.c
mprotect.c
mremap.c
msync.c
nommu.c
oom_kill.c mm/oom_kill: fix kernel-doc 2008-03-19 18:53:35 -07:00
page_alloc.c
page_io.c
page_isolation.c
page-writeback.c
pagewalk.c mm: fix various kernel-doc comments 2008-03-19 18:53:35 -07:00
pdflush.c
prio_tree.c
quicklist.c
readahead.c mm/readahead: fix kernel-doc notation 2008-03-19 18:53:37 -07:00
rmap.c mm: rmap kernel-doc fixes 2008-03-19 18:53:35 -07:00
shmem_acl.c
shmem.c mm/shmem and tiny-shmem: fix some kernel-doc 2008-03-19 18:53:35 -07:00
slab.c slab: fix cache_cache bootstrap in kmem_cache_init() 2008-03-26 10:44:17 -07:00
slob.c
slub.c count_partial() is not used if !SLUB_DEBUG and !CONFIG_SLABINFO 2008-03-26 10:42:28 -07:00
sparse-vmemmap.c
sparse.c
swap_state.c mm: fix various kernel-doc comments 2008-03-19 18:53:35 -07:00
swap.c mm: fix various kernel-doc comments 2008-03-19 18:53:35 -07:00
swapfile.c
thrash.c
tiny-shmem.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2008-03-25 08:57:47 -07:00
truncate.c
util.c
vmalloc.c mm: fix various kernel-doc comments 2008-03-19 18:53:35 -07:00
vmscan.c revert "kswapd should only wait on IO if there is IO" 2008-03-24 19:22:19 -07:00
vmstat.c