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[109.81.89.64]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-aab963cdfa5sm442501466b.199.2024.12.17.04.54.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Dec 2024 04:54:35 -0800 (PST) Date: Tue, 17 Dec 2024 13:54:35 +0100 From: Michal Hocko To: Chen Ridong Cc: akpm@linux-foundation.org, hannes@cmpxchg.org, yosryahmed@google.com, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, davidf@vimeo.com, vbabka@suse.cz, handai.szj@taobao.com, rientjes@google.com, kamezawa.hiroyu@jp.fujitsu.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, chenridong@huawei.com, wangweiyang2@huawei.com Subject: Re: [PATCH v1] memcg: fix soft lockup in the OOM process Message-ID: References: <20241217121828.3219752-1-chenridong@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241217121828.3219752-1-chenridong@huaweicloud.com> On Tue 17-12-24 12:18:28, Chen Ridong wrote: [...] > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > index 1c485beb0b93..14260381cccc 100644 > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -390,6 +390,7 @@ static int dump_task(struct task_struct *p, void *arg) > if (!is_memcg_oom(oc) && !oom_cpuset_eligible(p, oc)) > return 0; > > + cond_resched(); > task = find_lock_task_mm(p); > if (!task) { > /* This is called from RCU read lock for the global OOM killer path and I do not think you can schedule there. I do not remember specifics of task traversal for crgoup path but I guess that you might need to silence the soft lockup detector instead or come up with a different iteration scheme. -- Michal Hocko SUSE Labs