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charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 9ACC91C0013 X-Rspamd-Server: rspam09 X-Rspam-User: X-Stat-Signature: bfgmi34xzxfji9t53cgfb6odyrairnie X-HE-Tag: 1678788969-739428 X-HE-Meta: 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 MvRAyYVI f0BqnFl21stwcp/LCnSh9ot12tsBnQ/Uq3J946VnjEzAjAHXHG5vcfbgA064YVDbzzRwSrEt3sgeX2YVJ41ga1GpU3ot6KWCG3smZf5EtlRgqaTFu7te+e1TcR9o3LyhHRI6a41WSfiANmks5h98W/vYfuY2n7tlyNdd+4crGrt263agprYLpNcsxf3pwOQrFumcd9TRl3Ca1b13tCtRkgH4ZrA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue 14-03-23 18:07:42, Haifeng Xu wrote: > > > On 2023/3/14 17:19, Michal Hocko wrote: > > On Tue 14-03-23 09:11:36, Haifeng Xu wrote: > >> If oom_group is set, oom_kill_process() invokes oom_kill_memcg_member() > >> to kill all processes in the memcg. When scanning tasks in memcg, maybe > >> the provided task is marked as oom victim. Also, some tasks are likely > >> to release their address space. There is no need to kill the exiting tasks. > > > > This doesn't state any actual problem. Could you be more specific? Is > > this a bug fix, a behavior change or an optimization? > > > 1) oom_kill_process() has inovked __oom_kill_process() to kill the selected victim, but it will be scanned > in mem_cgroup_scan_tasks(). It's pointless to kill the victim twice. Why does that matter though? The purpose of task_will_free_mem in oom_kill_process is different. It would bail out from a potentially noisy OOM report when the selected oom victim is expected to terminate soon. __oom_kill_process called for the whole memcg doesn't aim at avoiding any oom victims. It merely sends a kill signal too all of them. > 2) for those exiting processes, reaping them directly is also a faster way to free memory compare with invoking > __oom_kill_process(). Is it? What if the terminating task is blocked on lock? Async oom reaping might release those resources in that case. -- Michal Hocko SUSE Labs