From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 7F4076B02FD for ; Wed, 21 Jun 2017 17:20:14 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id s74so169795603pfe.10 for ; Wed, 21 Jun 2017 14:20:14 -0700 (PDT) Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com. [67.231.145.42]) by mx.google.com with ESMTPS id 7si15318238pll.337.2017.06.21.14.20.12 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 21 Jun 2017 14:20:12 -0700 (PDT) From: Roman Gushchin Subject: [v3 3/6] mm, oom: cgroup-aware OOM killer debug info Date: Wed, 21 Jun 2017 22:19:13 +0100 Message-ID: <1498079956-24467-4-git-send-email-guro@fb.com> In-Reply-To: <1498079956-24467-1-git-send-email-guro@fb.com> References: <1498079956-24467-1-git-send-email-guro@fb.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: Roman Gushchin , Tejun Heo , Johannes Weiner , Li Zefan , Michal Hocko , Vladimir Davydov , Tetsuo Handa , kernel-team@fb.com, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Dump the cgroup oom badness score, as well as the name of chosen victim cgroup. Here how it looks like in dmesg: [ 18.824495] Choosing a victim memcg because of the system-wide OOM [ 18.826911] Cgroup /A1: 200805 [ 18.827996] Cgroup /A2: 273072 [ 18.828937] Cgroup /A2/B3: 51 [ 18.829795] Cgroup /A2/B4: 272969 [ 18.830800] Cgroup /A2/B5: 52 [ 18.831890] Chosen cgroup /A2/B4: 272969 Signed-off-by: Roman Gushchin Cc: Tejun Heo Cc: Johannes Weiner Cc: Li Zefan Cc: Michal Hocko Cc: Vladimir Davydov Cc: Tetsuo Handa Cc: kernel-team@fb.com Cc: cgroups@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org --- mm/memcontrol.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index bdb5103..4face20 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2669,7 +2669,15 @@ bool mem_cgroup_select_oom_victim(struct oom_control *oc) if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) return false; + + pr_info("Choosing a victim memcg because of the %s", + oc->memcg ? + "memory limit reached of cgroup " : + "system-wide OOM\n"); if (oc->memcg) { + pr_cont_cgroup_path(oc->memcg->css.cgroup); + pr_cont("\n"); + chosen_memcg = oc->memcg; parent = oc->memcg; } @@ -2683,6 +2691,10 @@ bool mem_cgroup_select_oom_victim(struct oom_control *oc) points = mem_cgroup_oom_badness(iter, oc->nodemask); + pr_info("Cgroup "); + pr_cont_cgroup_path(iter->css.cgroup); + pr_cont(": %ld\n", points); + if (points > chosen_memcg_points) { chosen_memcg = iter; chosen_memcg_points = points; @@ -2731,6 +2743,10 @@ bool mem_cgroup_select_oom_victim(struct oom_control *oc) oc->chosen_memcg = chosen_memcg; } + pr_info("Chosen cgroup "); + pr_cont_cgroup_path(chosen_memcg->css.cgroup); + pr_cont(": %ld\n", oc->chosen_points); + /* * Even if we have to kill all tasks in the cgroup, * we need to select the biggest task to start with. @@ -2739,7 +2755,9 @@ bool mem_cgroup_select_oom_victim(struct oom_control *oc) */ oc->chosen_points = 0; mem_cgroup_scan_tasks(chosen_memcg, oom_evaluate_task, oc); - } + } else if (oc->chosen) + pr_info("Chosen task %s (%d) in root cgroup: %ld\n", + oc->chosen->comm, oc->chosen->pid, oc->chosen_points); rcu_read_unlock(); -- 2.7.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org