lkml.org 
[lkml]   [2009]   [Jul]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] page-allocator: Ensure that processes that have been OOM killed exit the page allocator (resend)
Processes that have been OOM killed set the thread flag TIF_MEMDIE. A process
such as this is expected to exit the page allocator but potentially, it
loops forever. This patch checks TIF_MEMDIE when deciding whether to loop
again in the page allocator. If set, and __GFP_NOFAIL is not specified
then the loop will exit on the assumption it's no longer important for the
process to make forward progress. Note that a process that has just been
OOM-killed will still loop at least one more time retrying the allocation
before the thread flag is checked.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
---
mm/page_alloc.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index f8902e7..5c98d02 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1547,6 +1547,14 @@ should_alloc_retry(gfp_t gfp_mask, unsigned int order,
if (gfp_mask & __GFP_NORETRY)
return 0;

+ /* Do not loop if OOM-killed unless __GFP_NOFAIL is specified */
+ if (test_thread_flag(TIF_MEMDIE)) {
+ if (gfp_mask & __GFP_NOFAIL)
+ WARN(1, "Potential infinite loop with __GFP_NOFAIL");
+ else
+ return 0;
+ }
+
/*
* In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
* means __GFP_NOFAIL, but that may not be true in other

\
 
 \ /
  Last update: 2009-07-15 12:51    [W:0.077 / U:7.020 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site