Re: [REPOST] [PATCH 2/2] mm,oom: Reverse the order of setting TIF_MEMDIE and sending SIGKILL.
From: Michal Hocko <mhocko@kernel.org>
Date: 2015-08-26 14:12:37
Hi Oleg, On Sun 23-08-15 16:19:38, Tetsuo Handa wrote: [...]
quoted hunk ↗ jump to hunk
diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 5249e7e..c0a5a69 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c@@ -555,12 +555,17 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p, /* Get a reference to safely compare mm after task_unlock(victim) */ mm = victim->mm; atomic_inc(&mm->mm_users); - mark_oom_victim(victim); pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB\n", task_pid_nr(victim), victim->comm, K(victim->mm->total_vm), K(get_mm_counter(victim->mm, MM_ANONPAGES)), K(get_mm_counter(victim->mm, MM_FILEPAGES))); task_unlock(victim); + /* Send SIGKILL before setting TIF_MEMDIE. */ + do_send_sig_info(SIGKILL, SEND_SIG_FORCED, victim, true); + task_lock(victim); + if (victim->mm) + mark_oom_victim(victim); + task_unlock(victim);
I cannot seem to find any explicit note about task_lock vs. signal nesting nor task_lock() anywhere in kernel/signal.c so I rather ask. Can we call do_send_sig_info with task_lock held? Thanks! -- Michal Hocko SUSE Labs -- 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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>