signals: microoptimize the usage of ->curr_target

db51aecc · Oleg Nesterov <[email protected]> · 2008-04-30 00:52:52 -07:00

Suggested by Roland McGrath.

Initialize signal->curr_target in copy_signal().  This way ->curr_target is
never == NULL, we can kill the check in __group_complete_signal's hot path.

Signed-off-by: Oleg Nesterov <[email protected]>
Cc: Roland McGrath <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: db51aeccd7097ce19a522a4c5ff91c320f870e2b
Parents: 08d2c30c

Changes

2 files changed · +1 −5

File	Status	Add	Del	Content
kernel/fork.c	modified	+1	−1	View file
kernel/signal.c	modified	+0	−4	View file

kernel/fork.c

View file

diff --git a/kernel/fork.c b/kernel/fork.c
index 068ffe0..2bb675a 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -892,7 +892,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
 	sig->group_exit_code = 0;
 	sig->group_exit_task = NULL;
 	sig->group_stop_count = 0;
-	sig->curr_target = NULL;
+	sig->curr_target = tsk;
 	init_sigpending(&sig->shared_pending);
 	INIT_LIST_HEAD(&sig->posix_timers);
 

kernel/signal.c

View file

diff --git a/kernel/signal.c b/kernel/signal.c
index 17859f0..0298bd3 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -863,10 +863,6 @@ __group_complete_signal(int sig, struct task_struct *p)
 		 * Otherwise try to find a suitable thread.
 		 */
 		t = signal->curr_target;
-		if (t == NULL)
-			/* restart balancing at this thread */
-			t = signal->curr_target = p;
-
 		while (!wants_signal(sig, t)) {
 			t = next_thread(t);
 			if (t == signal->curr_target)