提交 d359b549 编写于 作者: O Oleg Nesterov 提交者: Linus Torvalds

[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: NOleg Nesterov <oleg@tv-sign.ru>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
上级 44938af6
...@@ -389,7 +389,7 @@ static struct task_struct * futex_find_get_task(pid_t pid) ...@@ -389,7 +389,7 @@ static struct task_struct * futex_find_get_task(pid_t pid)
{ {
struct task_struct *p; struct task_struct *p;
read_lock(&tasklist_lock); rcu_read_lock();
p = find_task_by_pid(pid); p = find_task_by_pid(pid);
if (!p) if (!p)
goto out_unlock; goto out_unlock;
...@@ -403,7 +403,7 @@ static struct task_struct * futex_find_get_task(pid_t pid) ...@@ -403,7 +403,7 @@ static struct task_struct * futex_find_get_task(pid_t pid)
} }
get_task_struct(p); get_task_struct(p);
out_unlock: out_unlock:
read_unlock(&tasklist_lock); rcu_read_unlock();
return p; return p;
} }
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册
新手
引导
客服 返回
顶部