From 29fd66d289f2981e11c550f8b411a6d3d38be0cf Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Wed, 28 Mar 2012 14:42:41 -0700 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 Cc: Mel Gorman Cc: KAMEZAWA Hiroyuki Cc: Minchan Kim Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'mm') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index caea788628e..c313afcc8e5 100644 --- a/mm/page_alloc.c +++ b/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, -- cgit v1.2.3-18-g5258