From 26e75b5c3d2226cb995fde064744aa93f63849c4 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 10 Dec 2014 15:54:54 -0800 Subject: [PATCH] exit: release_task: fix the comment about group leader accounting Contrary to what the comment in __exit_signal() says we do account the group leader. Fix this and explain why. Signed-off-by: Oleg Nesterov Cc: Aaron Tomlin Cc: "Eric W. Biederman" Cc: Rik van Riel Cc: Sterling Alexander Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/kernel/exit.c b/kernel/exit.c index 6297eb0f5bd2..9a65f10dc9ff 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -118,13 +118,10 @@ static void __exit_signal(struct task_struct *tsk) } /* - * Accumulate here the counters for all threads but the group leader - * as they die, so they can be added into the process-wide totals - * when those are taken. The group leader stays around as a zombie as - * long as there are other threads. When it gets reaped, the exit.c - * code will add its counts into these totals. We won't ever get here - * for the group leader, since it will have been the last reference on - * the signal_struct. + * Accumulate here the counters for all threads as they die. We could + * skip the group leader because it is the last user of signal_struct, + * but we want to avoid the race with thread_group_cputime() which can + * see the empty ->thread_head list. */ task_cputime(tsk, &utime, &stime); write_seqlock(&sig->stats_lock); -- 2.34.1