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| author | Lai Jiangshan <laijs@cn.fujitsu.com> | 2008-10-05 00:51:15 +0400 |
|---|---|---|
| committer | Alexey Dobriyan <adobriyan@gmail.com> | 2008-10-10 04:18:57 +0400 |
| commit | a6bebbc87a8c16eabb6bd5c6fd2d994be0236fba (patch) | |
| tree | 3e617ca49063f3a12c982da5d6c687882a1b4070 /fs/proc/array.c | |
| parent | 53167a3ef23df561d898dee636f3393e9fba937c (diff) | |
| download | linux-a6bebbc87a8c16eabb6bd5c6fd2d994be0236fba.tar.xz | |
[PATCH] signal, procfs: some lock_task_sighand() users do not need rcu_read_lock()
lock_task_sighand() make sure task->sighand is being protected,
so we do not need rcu_read_lock().
[ exec() will get task->sighand->siglock before change task->sighand! ]
But code using rcu_read_lock() _just_ to protect lock_task_sighand()
only appear in procfs. (and some code in procfs use lock_task_sighand()
without such redundant protection.)
Other subsystem may put lock_task_sighand() into rcu_read_lock()
critical region, but these rcu_read_lock() are used for protecting
"for_each_process()", "find_task_by_vpid()" etc. , not for protecting
lock_task_sighand().
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
[ok from Oleg]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Diffstat (limited to 'fs/proc/array.c')
| -rw-r--r-- | fs/proc/array.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c index 71c9be59c9c2..1c8d7b5d7a14 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -261,7 +261,6 @@ static inline void task_sig(struct seq_file *m, struct task_struct *p) sigemptyset(&ignored); sigemptyset(&caught); - rcu_read_lock(); if (lock_task_sighand(p, &flags)) { pending = p->pending.signal; shpending = p->signal->shared_pending.signal; @@ -272,7 +271,6 @@ static inline void task_sig(struct seq_file *m, struct task_struct *p) qlim = p->signal->rlim[RLIMIT_SIGPENDING].rlim_cur; unlock_task_sighand(p, &flags); } - rcu_read_unlock(); seq_printf(m, "Threads:\t%d\n", num_threads); seq_printf(m, "SigQ:\t%lu/%lu\n", qsize, qlim); |