linux/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 alloc_percpu() fails to allocate percpu data 2008-03-04 16:35:11 -08:00
backing-dev.c mm/backing-dev.c: fix percpu_counter_destroy call bug in bdi_init 2007-12-05 09:21:18 -08:00
bootmem.c mm: fix boundary checking in free_bootmem_core 2008-03-24 19:22:19 -07:00
bounce.c block: Initial support for data-less (or empty) barrier support 2007-10-16 11:03:56 +02:00
dmapool.c pool: Improve memory usage for devices which can't cross boundaries 2007-12-04 10:39:58 -05:00
fadvise.c check ADVICE of fadvise64_64 even if get_xip_page is given 2008-02-05 09:44:19 -08:00
filemap_xip.c Use pgoff_t instead of unsigned long 2008-02-08 09:22:32 -08:00
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 Solve section mismatch for free_area_init_core. 2008-02-23 17:13:24 -08:00
Kconfig sh: Bump number of quicklists for SH-5. 2008-01-28 13:18:55 +09:00
madvise.c speed up madvise_need_mmap_write() usage 2007-07-16 09:05:36 -07:00
Makefile Memory controller: rename to Memory Resource Controller 2008-03-04 16:35:12 -08:00
memcontrol.c memcgroup: fix check for thread being a group leader in memcgroup 2008-03-19 18:53:35 -07:00
memory_hotplug.c Page allocator: clean up pcp draining functions 2008-02-05 09:44:17 -08:00
memory.c memcg: when do_swap's do_wp_page fails 2008-03-04 16:35:14 -08:00
mempolicy.c mempolicy: fix reference counting bugs 2008-03-10 18:01:19 -07:00
mempool.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
migrate.c memcg: fix VM_BUG_ON from page migration 2008-03-04 16:35:14 -08:00
mincore.c [PATCH] mincore: vma crossing fix 2007-02-15 09:57:03 -08:00
mlock.c do not limit locked memory when RLIMIT_MEMLOCK is RLIM_INFINITY 2007-07-16 09:05:37 -07:00
mmap.c mm: special mapping nopage 2008-02-08 18:57:39 -08:00
mmzone.c [PATCH] remove EXPORT_UNUSED_SYMBOL'ed symbols 2006-12-07 08:39:44 -08:00
mprotect.c fix mprotect vma_wants_writenotify prot 2007-10-23 08:32:06 -07:00
mremap.c sparse pointer use of zero as null 2007-10-18 14:37:31 -07:00
msync.c Detach sched.h from mm.h 2007-05-21 09:18:19 -07:00
nommu.c nommu: add new vmalloc_user() and remap_vmalloc_range() interfaces. 2008-02-05 09:44:21 -08:00
oom_kill.c mm/oom_kill: fix kernel-doc 2008-03-19 18:53:35 -07:00
page_alloc.c memcg: bad page if page_cgroup when free 2008-03-04 16:35:15 -08:00
page_io.c mm: fix PageUptodate data race 2008-02-05 09:44:19 -08:00
page_isolation.c memory hotremove: unset migrate type "ISOLATE" after removal 2007-11-14 18:45:38 -08:00
page-writeback.c writeback: speed up writeback of big dirty files 2008-02-05 09:44:19 -08:00
pagewalk.c mm: fix various kernel-doc comments 2008-03-19 18:53:35 -07:00
pdflush.c Freezer: make kernel threads nonfreezable by default 2007-07-17 10:23:02 -07:00
prio_tree.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
quicklist.c quicklists: Only consider memory that can be used with GFP_KERNEL 2008-01-14 08:52:22 -08:00
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 [PATCH] Fix typos in mm/shmem_acl.c 2006-10-11 11:14:23 -07:00
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 slob: reduce external fragmentation by using three free lists 2008-02-05 09:44:19 -08:00
slub.c count_partial() is not used if !SLUB_DEBUG and !CONFIG_SLABINFO 2008-03-26 10:42:28 -07:00
sparse-vmemmap.c memory hotplug fix: fix section mismatch in vmammap_allock_block() 2007-11-29 09:24:54 -08:00
sparse.c mm: fix section mismatch warning in sparse.c 2008-02-05 09:44:19 -08:00
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 d_path: Make seq_path() use a struct path argument 2008-02-14 21:17:08 -08:00
thrash.c Bug in mm/thrash.c function grab_swap_token() 2007-05-11 08:29:32 -07:00
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 docbook: fix kernel-api source files 2008-03-03 10:47:14 -08:00
util.c fix mm/util.c:krealloc() 2007-11-14 18:45:41 -08:00
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 vmstat: remove prefetch 2008-02-05 09:44:18 -08:00