+ memcg-make-oom-killer-a-no-op-when-no-killable-task-can-be-found.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     memcg: make oom killer a no-op when no killable task can be found
has been added to the -mm tree.  Its filename is
     memcg-make-oom-killer-a-no-op-when-no-killable-task-can-be-found.patch

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------------------------------------------------------
Subject: memcg: make oom killer a no-op when no killable task can be found
From: David Rientjes <rientjes@google.com>

It's pointless to try to kill current if select_bad_process() did not find
an eligible task to kill in mem_cgroup_out_of_memory() since it's
guaranteed that current is a member of the memcg that is oom and it is, by
definition, unkillable.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/oom_kill.c |    5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff -puN mm/oom_kill.c~memcg-make-oom-killer-a-no-op-when-no-killable-task-can-be-found mm/oom_kill.c
--- a/mm/oom_kill.c~memcg-make-oom-killer-a-no-op-when-no-killable-task-can-be-found
+++ a/mm/oom_kill.c
@@ -512,12 +512,9 @@ void mem_cgroup_out_of_memory(struct mem
 	read_lock(&tasklist_lock);
 retry:
 	p = select_bad_process(&points, limit, mem, CONSTRAINT_NONE, NULL);
-	if (PTR_ERR(p) == -1UL)
+	if (!p || PTR_ERR(p) == -1UL)
 		goto out;
 
-	if (!p)
-		p = current;
-
 	if (oom_kill_process(p, gfp_mask, 0, points, limit, mem,
 				"Memory cgroup out of memory"))
 		goto retry;
_

Patches currently in -mm which might be from rientjes@google.com are

linux-next.patch
hugetlbfs-kill-applications-that-use-map_noreserve-with-sigbus-instead-of-oom-killer.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-reintroduce-and-deprecate-oom_kill_allocating_task.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
oom-select_bad_process-check-pf_kthread-instead-of-mm-to-skip-kthreads.patch
oom-select_bad_process-pf_exiting-check-should-take-mm-into-account.patch
oom-introduce-find_lock_task_mm-to-fix-mm-false-positives.patch
oom-oom_forkbomb_penalty-move-thread_group_cputime-out-of-task_lock.patch
oom-hold-tasklist_lock-when-dumping-tasks.patch
oom-give-current-access-to-memory-reserves-if-it-has-been-killed.patch
oom-avoid-sending-exiting-tasks-a-sigkill.patch
oom-clean-up-oom_kill_task.patch
oom-clean-up-oom_badness.patch
oom-select_bad_process-never-choose-tasks-with-badness-==-0.patch
oom-avoid-divide-by-zero.patch
mempolicy-remove-case-mpol_interleave-from-policy_zonelist.patch
mempolicy-remove-redundant-check.patch
mempolicy-dont-call-mpol_set_nodemask-when-no_context.patch
mempolicy-lose-unnecessary-loop-variable-in-mpol_parse_str.patch
mempolicy-rename-policy_types-and-cleanup-initialization.patch
mempolicy-factor-mpol_shared_policy_init-return-paths.patch
mempolicy-document-cpuset-interaction-with-tmpfs-mpol-mount-option.patch
mm-default-to-node-zonelist-ordering-when-nodes-have-only-lowmem.patch
oom-move-sysctl-declarations-to-oomh.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
memcg-make-oom-killer-a-no-op-when-no-killable-task-can-be-found.patch
numa-add-generic-percpu-var-numa_node_id-implementation.patch
numa-x86_64-use-generic-percpu-var-numa_node_id-implementation.patch
numa-ia64-use-generic-percpu-var-numa_node_id-implementation.patch
numa-introduce-numa_mem_id-effective-local-memory-node-id.patch
numa-ia64-support-numa_mem_id-for-memoryless-nodes.patch
numa-slab-use-numa_mem_id-for-slab-local-memory-node.patch
numa-in-kernel-profiling-use-cpu_to_mem-for-per-cpu-allocations.patch
numa-update-documentation-vm-numa-add-memoryless-node-info.patch