Commit 299c517a authored Feb 24, 2017 by David Rientjes Committed by Linus Torvalds Feb 24, 2017

mm, oom: header nodemask is NULL when cpusets are disabled

Commit 82e7d3ab ("oom: print nodemask in the oom report") implicitly
sets the allocation nodemask to cpuset_current_mems_allowed when there
is no effective mempolicy.  cpuset_current_mems_allowed is only
effective when cpusets are enabled, which is also printed by
dump_header(), so setting the nodemask to cpuset_current_mems_allowed is
redundant and prevents debugging issues where ac->nodemask is not set
properly in the page allocator.

This provides better debugging output since
cpuset_print_current_mems_allowed() is already provided.

[rientjes@google.com: newline per Hillf]
  Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1701200158300.88321@chino.kir.corp.google.com
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1701191454470.2381@chino.kir.corp.google.com


Signed-off-by: David Rientjes <rientjes@google.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent e86c59b1

mm/oom_kill.c

+9 −7

Original line number	Diff line number	Diff line
		@@ -403,12 +403,14 @@ static void dump_tasks(struct mem_cgroup memcg, const nodemask_t nodemask)

		static void dump_header(struct oom_control oc, struct task_struct p)
		{
		nodemask_t *nm = (oc->nodemask) ? oc->nodemask : &cpuset_current_mems_allowed;

		pr_warn("%s invoked oom-killer: gfp_mask=%#x(%pGg), nodemask=%*pbl, order=%d, oom_score_adj=%hd\n",
		current->comm, oc->gfp_mask, &oc->gfp_mask,
		nodemask_pr_args(nm), oc->order,
		current->signal->oom_score_adj);
		pr_warn("%s invoked oom-killer: gfp_mask=%#x(%pGg), nodemask=",
		current->comm, oc->gfp_mask, &oc->gfp_mask);
		if (oc->nodemask)
		pr_cont("%*pbl", nodemask_pr_args(oc->nodemask));
		else
		pr_cont("(null)");
		pr_cont(", order=%d, oom_score_adj=%hd\n",
		oc->order, current->signal->oom_score_adj);
		if (!IS_ENABLED(CONFIG_COMPACTION) && oc->order)
		pr_warn("COMPACTION is disabled!!!\n");

		@@ -417,7 +419,7 @@ static void dump_header(struct oom_control oc, struct task_struct p)
		if (oc->memcg)
		mem_cgroup_print_oom_info(oc->memcg, p);
		else
		show_mem(SHOW_MEM_FILTER_NODES, nm);
		show_mem(SHOW_MEM_FILTER_NODES, oc->nodemask);
		if (sysctl_oom_dump_tasks)
		dump_tasks(oc->memcg, oc->nodemask);
		}

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