From d359b549bf3d7f42f0084918a4816ea4572e507c Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 29 Sep 2006 02:00:55 -0700 Subject: [PATCH] [PATCH] futex_find_get_task(): don't take tasklist_lock It is ok to do find_task_by_pid() + get_task_struct() under rcu_read_lock(), we cand drop tasklist_lock. Note that testing of ->exit_state is racy with or without tasklist anyway. Signed-off-by: Oleg Nesterov Acked-by: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/futex.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/futex.c b/kernel/futex.c index 9d260e838c..ca8ef11feb 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -389,7 +389,7 @@ static struct task_struct * futex_find_get_task(pid_t pid) { struct task_struct *p; - read_lock(&tasklist_lock); + rcu_read_lock(); p = find_task_by_pid(pid); if (!p) goto out_unlock; @@ -403,7 +403,7 @@ static struct task_struct * futex_find_get_task(pid_t pid) } get_task_struct(p); out_unlock: - read_unlock(&tasklist_lock); + rcu_read_unlock(); return p; } -- 2.39.5