Messages in this thread Patch in this message | | | Date | Mon, 21 Aug 2006 21:06:21 +0400 | From | Oleg Nesterov <> | Subject | [PATCH 2/3] futex_find_get_task: don't take tasklist_lock |
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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 <oleg@tv-sign.ru>
--- 2.6.18-rc4/kernel/futex.c~2_ffgt 2006-08-21 20:32:48.000000000 +0400 +++ 2.6.18-rc4/kernel/futex.c 2006-08-21 20:41:15.000000000 +0400 @@ -389,7 +389,7 @@ static struct task_struct * futex_find_g { 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_g } get_task_struct(p); out_unlock: - read_unlock(&tasklist_lock); + rcu_read_unlock(); return p; } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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