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charset=UTF-8 Content-Transfer-Encoding: 7bit X-CM-TRANSID:Syh0CgDnk+BifWJnef6VEw--.45928S2 X-Coremail-Antispam: 1UD129KBjvJXoW7tFW3ur4kJw1DWrWkJr1xAFb_yoW8Xr48pa 95WayaywsYyFWFqr1Ivw4vqry3Z3yIkrWagr4jkr1rKrn8Wa4S9Fyjy3y3JrWfuFn2yF12 9r4q9rnrJrs0yaDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUv0b4IE77IF4wAFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x 0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG 6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFV Cjc4AY6r1j6r4UM4x0Y48IcVAKI48JM4IIrI8v6xkF7I0E8cxan2IY04v7MxkF7I0En4kS 14v26r4a6rW5MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I 8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVW8ZVWr XwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x 0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_ Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU0 s2-5UUUUU== X-CM-SenderInfo: hfkh02xlgr0w46kxt4xhlfz01xgou0bp/ X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 9568214000A X-Stat-Signature: orqwikdwud78pbwwnbdqn7qxxyuejsit X-Rspam-User: X-HE-Tag: 1734507860-295022 X-HE-Meta: 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 uFbIRtAr v/3F6N2PHL0k2d3cxIB0kyeLxJmq0zrPxKMdCzPQSpnAqK8Kw1d7hDisXX+vSL8NL09Awnfz/GEiSF4QbyE3W9XlHfob7ICu3ujRyaxoYZe0Y63qrwvfqi9fTi5uxEv7X67HsqpZKcdpL/CjCqTxu6HsSp+Sp+yQvUOTX 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: List-Subscribe: List-Unsubscribe: On 2024/12/17 20:54, Michal Hocko wrote: > 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. Thank you, Michal. I made a mistake. I added cond_resched in the mem_cgroup_scan_tasks function below the fn, but after reconsideration, it may cause unnecessary scheduling for other callers of mem_cgroup_scan_tasks. Therefore, I moved it into the dump_task function. However, I missed the RCU lock from the global OOM. I think we can use touch_nmi_watchdog in place of cond_resched, which can silence the soft lockup detector. Do you think that is acceptable? @@ -390,7 +391,7 @@ static int dump_task(struct task_struct *p, void *arg) if (!is_memcg_oom(oc) && !oom_cpuset_eligible(p, oc)) return 0; + touch_nmi_watchdog(); task = find_lock_task_mm(p); Best regards, Ridong