linux/mm
Hugh Dickins d952b79136 ksm: fix endless loop on oom
break_ksm has been looping endlessly ignoring VM_FAULT_OOM: that should
only be a problem for ksmd when a memory control group imposes limits
(normally the OOM killer will kill others with an mm until it succeeds);
but in general (especially for MADV_UNMERGEABLE and KSM_RUN_UNMERGE) we
do need to route the error (or kill) back to the caller (or sighandling).

Test signal_pending in unmerge_ksm_pages, which could be a lengthy
procedure if it has to spill into swap: returning -ERESTARTSYS so that
trivial signals will restart but fatals will terminate (is that right?
we do different things in different places in mm, none exactly this).

unmerge_and_remove_all_rmap_items was forgetting to lock when going
down the mm_list: fix that.  Whether it's successful or not, reset
ksm_scan cursor to head; but only if it's successful, reset seqnr
(shown in full_scans) - page counts will have gone down to zero.

This patch leaves a significant OOM deadlock, but it's a good step
on the way, and that deadlock is fixed in a subsequent patch.

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Acked-by: Izik Eidus <ieidus@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:32 -07:00
..
allocpercpu.c
backing-dev.c writeback: splice dirty inode entries to default bdi on bdi_destroy() 2009-09-16 15:18:52 +02:00
bootmem.c kmemleak: Do not report alloc_bootmem blocks as leaks 2009-08-27 14:29:17 +01:00
bounce.c
debug-pagealloc.c
dmapool.c
fadvise.c
failslab.c
filemap_xip.c
filemap.c mm: oom analysis: add shmem vmstat 2009-09-22 07:17:27 -07:00
fremap.c
highmem.c
hugetlb.c hugetlb: restore interleaving of bootmem huge pages 2009-09-22 07:17:26 -07:00
init-mm.c
internal.h
Kconfig ksm: the mm interface to ksm 2009-09-22 07:17:31 -07:00
Kconfig.debug
kmemcheck.c
kmemleak-test.c
kmemleak.c kmemleak: Improve the "Early log buffer exceeded" error message 2009-09-11 10:42:09 +01:00
ksm.c ksm: fix endless loop on oom 2009-09-22 07:17:32 -07:00
maccess.c
madvise.c ksm: the mm interface to ksm 2009-09-22 07:17:31 -07:00
Makefile ksm: the mm interface to ksm 2009-09-22 07:17:31 -07:00
memcontrol.c cgroup avoid permanent sleep at rmdir 2009-07-29 19:10:35 -07:00
memory_hotplug.c memory hotplug: update zone pcp at memory online 2009-09-22 07:17:25 -07:00
memory.c ksm: identify PageKsm pages 2009-09-22 07:17:31 -07:00
mempolicy.c mm: make set_mempolicy(MPOL_INTERLEAV) N_HIGH_MEMORY aware 2009-08-07 10:39:55 -07:00
mempool.c mempool.c: clean up type-casting 2009-08-10 08:31:16 -07:00
migrate.c mm: vmstat: add isolate pages 2009-09-22 07:17:29 -07:00
mincore.c
mlock.c
mm_init.c
mmap.c perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
mmu_notifier.c ksm: add mmu_notifier set_pte_at_notify() 2009-09-22 07:17:31 -07:00
mmzone.c
mprotect.c perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
mremap.c ksm: prevent mremap move poisoning 2009-09-22 07:17:31 -07:00
msync.c
nommu.c nommu: fix error handling in do_mmap_pgoff() 2009-09-05 11:30:42 -07:00
oom_kill.c mm: revert "oom: move oom_adj value" 2009-08-18 16:31:13 -07:00
page_alloc.c mm: perform non-atomic test-clear of PG_mlocked on free 2009-09-22 07:17:30 -07:00
page_cgroup.c memory hotplug: alloc page from other node in memory online 2009-09-22 07:17:26 -07:00
page_io.c
page_isolation.c
page-writeback.c mm: count only reclaimable lru pages 2009-09-22 07:17:30 -07:00
pagewalk.c
percpu.c Merge branch 'for-next' into for-linus 2009-09-15 09:57:19 +09:00
prio_tree.c
quicklist.c
readahead.c
rmap.c ksm: no debug in page_dup_rmap() 2009-09-22 07:17:31 -07:00
shmem_acl.c shmfs: use 'check_acl' instead of 'permission' 2009-09-08 11:08:46 -07:00
shmem.c Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev 2009-09-15 09:50:49 -07:00
slab.c
slob.c slab: remove duplicate kmem_cache_init_late() declarations 2009-08-06 11:36:25 +03:00
slub.c slub: Fix build error in kmem_cache_open() with !CONFIG_SLUB_DEBUG 2009-09-15 22:32:10 +03:00
sparse-vmemmap.c memory hotplug: alloc page from other node in memory online 2009-09-22 07:17:26 -07:00
sparse.c memory hotplug: alloc page from other node in memory online 2009-09-22 07:17:26 -07:00
swap_state.c writeback: add name to backing_dev_info 2009-09-11 09:20:26 +02:00
swap.c
swapfile.c block: use blkdev_issue_discard in blk_ioctl_discard 2009-09-14 08:24:53 +02:00
thrash.c
truncate.c
util.c
vmalloc.c vmalloc.c: fix double error checking 2009-09-22 07:17:30 -07:00
vmscan.c vmscan: kill unnecessary prefetch 2009-09-22 07:17:30 -07:00
vmstat.c mm: vmstat: add isolate pages 2009-09-22 07:17:29 -07:00