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| author | Oleg Nesterov <oleg@tv-sign.ru> | 2006-09-29 02:00:55 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-09-29 09:18:18 -0700 |
| commit | d359b549bf3d7f42f0084918a4816ea4572e507c (patch) | |
| tree | a154a9b1913a459bdaed49c623d39f1e73689295 /kernel/futex.c | |
| parent | 44938af6e08580514abce8bea23ae1c034ea0b1d (diff) | |
| download | lwn-d359b549bf3d7f42f0084918a4816ea4572e507c.tar.gz lwn-d359b549bf3d7f42f0084918a4816ea4572e507c.zip | |
[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 <oleg@tv-sign.ru>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/futex.c')
| -rw-r--r-- | kernel/futex.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index 9d260e838cff..ca8ef11feb65 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; } |