proc: get_nr_threads() doesn't need ->siglock any longer
Now that task->signal can't go away get_nr_threads() doesn't need
->siglock to read signal->count.
Also, make it inline, move into sched.h, and convert 2 other proc users of
signal->count to use this (now trivial) helper.
Henceforth get_nr_threads() is the only valid user of signal->count, we
are ready to turn it into "int nr_threads" or, perhaps, kill it.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index dd597d8..ccd2d15 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2147,6 +2147,11 @@
#define while_each_thread(g, t) \
while ((t = next_thread(t)) != g)
+static inline int get_nr_threads(struct task_struct *tsk)
+{
+ return atomic_read(&tsk->signal->count);
+}
+
/* de_thread depends on thread_group_leader not being a pid based check */
#define thread_group_leader(p) (p == p->group_leader)
