The patch titled
oom: default to killing current for pagefault ooms
has been added to the -mm tree. Its filename is
oom-default-to-killing-current-for-pagefault-ooms.patch
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------------------------------------------------------
Subject: oom: default to killing current for pagefault ooms
From: David Rientjes <rientjes@xxxxxxxxxx>
The pagefault oom handler does not know the context (gfp_mask, order, etc)
in which memory was not found when a VM_FAULT_OOM is generated. The only
information known is that current is trying to allocate in that context,
so killing it is a legitimate response (and is the default for
architectures that do not even use the pagefault oom handler such as ia64
and powerpc).
When a VM_FAULT_OOM occurs, the pagefault oom handler will now attempt to
kill current by default. If it is unkillable, the oom killer is called to
find a memory-hogging task to kill instead that will lead to future memory
freeing.
Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Nick Piggin <npiggin@xxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/oom_kill.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff -puN mm/oom_kill.c~oom-default-to-killing-current-for-pagefault-ooms mm/oom_kill.c
--- a/mm/oom_kill.c~oom-default-to-killing-current-for-pagefault-ooms
+++ a/mm/oom_kill.c
@@ -711,15 +711,23 @@ void out_of_memory(struct zonelist *zone
}
/*
- * The pagefault handler calls here because it is out of memory, so kill a
- * memory-hogging task. If a populated zone has ZONE_OOM_LOCKED set, a parallel
- * oom killing is already in progress so do nothing. If a task is found with
- * TIF_MEMDIE set, it has been killed so do nothing and allow it to exit.
+ * The pagefault handler calls here because it is out of memory, so kill current
+ * by default. If it's unkillable, then fallback to killing a memory-hogging
+ * task. If a populated zone has ZONE_OOM_LOCKED set, a parallel oom killing is
+ * already in progress so do nothing. If a task is found with TIF_MEMDIE set,
+ * it has been killed so do nothing and allow it to exit.
*/
void pagefault_out_of_memory(void)
{
+ unsigned long totalpages;
+ int err;
+
if (try_set_system_oom()) {
- out_of_memory(NULL, 0, 0, NULL);
+ constrained_alloc(NULL, 0, NULL, &totalpages);
+ err = oom_kill_process(current, 0, 0, 0, totalpages, NULL,
+ "Out of memory (pagefault)");
+ if (err)
+ out_of_memory(NULL, 0, 0, NULL);
clear_system_oom();
}
if (!test_thread_flag(TIF_MEMDIE))
_
Patches currently in -mm which might be from rientjes@xxxxxxxxxx are
linux-next.patch
cpuset-fix-the-problem-that-cpuset_mem_spread_node-returns-an-offline-node.patch
cpuset-alloc-nodemask_t-on-the-heap-rather-than-the-stack.patch
mempolicy-remove-redundant-code.patch
oom-filter-tasks-not-sharing-the-same-cpuset.patch
oom-sacrifice-child-with-highest-badness-score-for-parent.patch
oom-select-task-from-tasklist-for-mempolicy-ooms.patch
oom-remove-special-handling-for-pagefault-ooms.patch
oom-badness-heuristic-rewrite.patch
oom-deprecate-oom_adj-tunable.patch
oom-replace-sysctls-with-quick-mode.patch
oom-avoid-oom-killer-for-lowmem-allocations.patch
oom-remove-unnecessary-code-and-cleanup.patch
oom-default-to-killing-current-for-pagefault-ooms.patch
oom-avoid-race-for-oom-killed-tasks-detaching-mm-prior-to-exit.patch
memcg-oom-wakeup-filter.patch
memcg-oom-wakeup-filter-update.patch
memcg-oom-notifier.patch
memcg-oom-notifier-update.patch
memcg-oom-kill-disable-and-oom-status.patch
memcg-oom-kill-disable-and-oom-status-update.patch
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