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>

1 files changed, 0 insertions, 12 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index c7f9f23449d..c384e8b84df 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -166,18 +166,6 @@ static int get_fs_path(struct task_struct *task, struct path *path, bool root)
 	return result;
 }
 
-static int get_nr_threads(struct task_struct *tsk)
-{
-	unsigned long flags;
-	int count = 0;
-
-	if (lock_task_sighand(tsk, &flags)) {
-		count = atomic_read(&tsk->signal->count);
-		unlock_task_sighand(tsk, &flags);
-	}
-	return count;
-}
-
 static int proc_cwd_link(struct inode *inode, struct path *path)
 {
 	struct task_struct *task = get_proc_task(inode);