Commit 3750ef97 authored Dec 10, 2014 by Oleg Nesterov Committed by Linus Torvalds Dec 10, 2014

exit: reparent: s/while_each_thread/for_each_thread/ in find_new_reaper()



Change find_new_reaper() to use for_each_thread() instead of deprecated
while_each_thread().  We do not bother to check "thread != father" in the
1st loop, we can rely on PF_EXITING check.

Note: this means the minor behavioural change: for_each_thread() starts
from the group leader.  But this should be fine, nobody should make any
assumption about do_wait(__WNOTHREAD) when it comes to reparented tasks.
And this can avoid the pointless reparenting to a short-living thread
While zombie leaders are not that common.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 7d24e2df

kernel/exit.c

+3 −5

Original line number	Original line	Diff line number	Diff line
	@@ -473,8 +473,7 @@ static struct task_struct find_new_reaper(struct task_struct father)
	struct pid_namespace *pid_ns = task_active_pid_ns(father);		struct pid_namespace *pid_ns = task_active_pid_ns(father);
	struct task_struct *thread;		struct task_struct *thread;

	thread = father;		for_each_thread(father, thread) {
	while_each_thread(father, thread) {
	if (thread->flags & PF_EXITING)		if (thread->flags & PF_EXITING)
	continue;		continue;
	if (unlikely(pid_ns->child_reaper == father))		if (unlikely(pid_ns->child_reaper == father))
	@@ -511,11 +510,10 @@ static struct task_struct find_new_reaper(struct task_struct father)
	break;		break;
	if (!reaper->signal->is_child_subreaper)		if (!reaper->signal->is_child_subreaper)
	continue;		continue;
	thread = reaper;		for_each_thread(reaper, thread) {
	do {
	if (!(thread->flags & PF_EXITING))		if (!(thread->flags & PF_EXITING))
	return thread;		return thread;
	} while_each_thread(reaper, thread);		}
	}		}
	}		}