From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750941AbdAXKNN (ORCPT ); Tue, 24 Jan 2017 05:13:13 -0500 Received: from mx2.suse.de ([195.135.220.15]:44323 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750821AbdAXKNL (ORCPT ); Tue, 24 Jan 2017 05:13:11 -0500 Date: Tue, 24 Jan 2017 11:12:55 +0100 From: Michal Hocko To: David Rientjes Cc: Andrew Morton , Vlastimil Babka , Johannes Weiner , Mel Gorman , linux-mm@kvack.org, LKML Subject: Re: [patch] mm, oom: header nodemask is NULL when cpusets are disabled Message-ID: <20170124101255.GC6867@dhcp22.suse.cz> References: <279f10c2-3eaa-c641-094f-3070db67d84f@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 19-01-17 14:57:36, David Rientjes wrote: > Commit 82e7d3abec86 ("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. > > Suggested-by: Vlastimil Babka > Signed-off-by: David Rientjes With the removed \n addressed in the follow up fix Acked-by: Michal Hocko > --- > mm/oom_kill.c | 16 +++++++++------- > 1 file changed, 9 insertions(+), 7 deletions(-) > > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -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)\n"); > + 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); > } -- Michal Hocko SUSE Labs