The patch titled
Subject: mm, coredump: fail allocations when coredumping instead of oom killing
has been added to the -mm tree. Its filename is
mm-coredump-fail-allocations-when-coredumping-instead-of-oom-killing.patch
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From: David Rientjes <rientjes@xxxxxxxxxx>
Subject: mm, coredump: fail allocations when coredumping instead of oom killing
The size of coredump files is limited by RLIMIT_CORE, however, allocating
large amounts of memory results in three negative consequences:
- the coredumping process may be chosen for oom kill and quickly deplete
all memory reserves in oom conditions preventing further progress from
being made or tasks from exiting,
- the coredumping process may cause other processes to be oom killed
without fault of their own as the result of a SIGSEGV, for example, in
the coredumping process, or
- the coredumping process may result in a livelock while writing to the
dump file if it needs memory to allocate while other threads are in
the exit path waiting on the coredumper to complete.
This is fixed by implying __GFP_NORETRY in the page allocator for
coredumping processes when reclaim has failed so the allocations fail and
the process continues to exit.
Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 4 ++++
1 file changed, 4 insertions(+)
diff -puN mm/page_alloc.c~mm-coredump-fail-allocations-when-coredumping-instead-of-oom-killing mm/page_alloc.c
--- a/mm/page_alloc.c~mm-coredump-fail-allocations-when-coredumping-instead-of-oom-killing
+++ a/mm/page_alloc.c
@@ -2308,6 +2308,10 @@ rebalance:
if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
if (oom_killer_disabled)
goto nopage;
+ /* Coredumps can quickly deplete all memory reserves */
+ if ((current->flags & PF_DUMPCORE) &&
+ !(gfp_mask & __GFP_NOFAIL))
+ goto nopage;
page = __alloc_pages_may_oom(gfp_mask, order,
zonelist, high_zoneidx,
nodemask, preferred_zone,
_
Subject: Subject: mm, coredump: fail allocations when coredumping instead of oom killing
Patches currently in -mm which might be from rientjes@xxxxxxxxxx are
origin.patch
linux-next.patch
mm-coredump-fail-allocations-when-coredumping-instead-of-oom-killing.patch
signal-give-send_sig_forced-more-power-to-beat-signal_unkillable.patch
signal-cosmetic-s-from_ancestor_ns-force-in-prepare_signal-paths.patch
signal-oom_kill_task-use-send_sig_forced-instead-of-force_sig.patch
signal-zap_pid_ns_processes-s-send_sig_noinfo-send_sig_forced.patch
usermodehelper-introduce-umh_completesub_info.patch
usermodehelper-implement-umh_killable.patch
usermodehelper-kill-umh_wait-renumber-umh_-constants.patch
usermodehelper-____call_usermodehelper-doesnt-need-do_exit.patch
kmod-introduce-call_modprobe-helper.patch
kmod-make-__request_module-killable.patch
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