From b8534d7bd89df0cd41cd47bcd6733a05ea9a691a Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Sat, 28 Oct 2006 10:38:53 -0700 Subject: [PATCH] taskstats: kill ->taskstats_lock in favor of ->siglock signal_struct is (mostly) protected by ->sighand->siglock, I think we don't need ->taskstats_lock to protect ->stats. This also allows us to simplify the locking in fill_tgid(). Signed-off-by: Oleg Nesterov Cc: Shailabh Nagar Cc: Balbir Singh Cc: Jay Lan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/taskstats.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) (limited to 'kernel/taskstats.c') diff --git a/kernel/taskstats.c b/kernel/taskstats.c index 9aeee511a46..b2efda94615 100644 --- a/kernel/taskstats.c +++ b/kernel/taskstats.c @@ -241,11 +241,11 @@ static int fill_tgid(pid_t tgid, struct task_struct *tgidtsk, tsk = first; read_lock(&tasklist_lock); /* Start with stats from dead tasks */ - if (first->signal) { - spin_lock_irqsave(&first->signal->stats_lock, flags); + if (first->sighand) { + spin_lock_irqsave(&first->sighand->siglock, flags); if (first->signal->stats) memcpy(stats, first->signal->stats, sizeof(*stats)); - spin_unlock_irqrestore(&first->signal->stats_lock, flags); + spin_unlock_irqrestore(&first->sighand->siglock, flags); } do { @@ -276,7 +276,7 @@ static void fill_tgid_exit(struct task_struct *tsk) { unsigned long flags; - spin_lock_irqsave(&tsk->signal->stats_lock, flags); + spin_lock_irqsave(&tsk->sighand->siglock, flags); if (!tsk->signal->stats) goto ret; @@ -288,7 +288,7 @@ static void fill_tgid_exit(struct task_struct *tsk) */ delayacct_add_tsk(tsk->signal->stats, tsk); ret: - spin_unlock_irqrestore(&tsk->signal->stats_lock, flags); + spin_unlock_irqrestore(&tsk->sighand->siglock, flags); return; } @@ -464,15 +464,10 @@ void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats, size_t size; int is_thread_group; struct nlattr *na; - unsigned long flags; if (!family_registered || !tidstats) return; - spin_lock_irqsave(&tsk->signal->stats_lock, flags); - is_thread_group = tsk->signal->stats ? 1 : 0; - spin_unlock_irqrestore(&tsk->signal->stats_lock, flags); - rc = 0; /* * Size includes space for nested attributes @@ -480,6 +475,7 @@ void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats, size = nla_total_size(sizeof(u32)) + nla_total_size(sizeof(struct taskstats)) + nla_total_size(0); + is_thread_group = (tsk->signal->stats != NULL); if (is_thread_group) size = 2 * size; /* PID + STATS + TGID + STATS */ -- cgit v1.2.3