[PATCH] kill_pid_info: kill acquired_tasklist_lock

Kill acquired_tasklist_lock, sig_needs_tasklist() is very cheap nowadays.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/signal.c b/kernel/signal.c
index 5630255d2e2a958f6e58eea4596a62b0dea3f91a..ea4632bd40a0edb6238232ed42ffb5ebb3d68146 100644 (file)
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1119,19 +1119,18 @@ kill_pg_info(int sig, struct siginfo *info, pid_t pgrp)
 int kill_pid_info(int sig, struct siginfo *info, struct pid *pid)
 {
        int error;
-       int acquired_tasklist_lock = 0;
        struct task_struct *p;
 
        rcu_read_lock();
-       if (unlikely(sig_needs_tasklist(sig))) {
+       if (unlikely(sig_needs_tasklist(sig)))
                read_lock(&tasklist_lock);
-               acquired_tasklist_lock = 1;
-       }
+
        p = pid_task(pid, PIDTYPE_PID);
        error = -ESRCH;
        if (p)
                error = group_send_sig_info(sig, info, p);
-       if (unlikely(acquired_tasklist_lock))
+
+       if (unlikely(sig_needs_tasklist(sig)))
                read_unlock(&tasklist_lock);
        rcu_read_unlock();
        return error;