Commit 986094df authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

exit: wait: drop tasklist_lock before psig->c* accounting 



wait_task_zombie() no longer needs tasklist_lock to accumulate the
psig->c* counters, we can drop it right after cmpxchg(exit_state).

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f953ccd0

kernel/exit.c

+5 −7
Original line number Diff line number Diff line
@@ -1005,6 +1005,11 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) 
		EXIT_TRACE : EXIT_DEAD;

	if (cmpxchg(&p->exit_state, EXIT_ZOMBIE, state) != EXIT_ZOMBIE)

		return 0;

	/*

	 * We own this thread, nobody else can reap it.

	 */

	read_unlock(&tasklist_lock);

	sched_annotate_sleep();



	/*

	 * Check thread_group_leader() to exclude the traced sub-threads.
@@ -1064,13 +1069,6 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) 
		spin_unlock_irq(&current->sighand->siglock);

	}



	/*

	 * Now we are sure this task is interesting, and no other

	 * thread can reap it because we its state == DEAD/TRACE.

	 */

	read_unlock(&tasklist_lock);

	sched_annotate_sleep();



	retval = wo->wo_rusage

		? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;

	status = (p->signal->flags & SIGNAL_GROUP_EXIT)