From f646e227b88a164a841d6b6dd969d8a45272dd83 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 27 Apr 2011 19:18:39 +0200 Subject: signal: retarget_shared_pending: consider shared/unblocked signals only exit_signals() checks signal_pending() before retarget_shared_pending() but this is suboptimal. We can avoid the while_each_thread() loop in case when there are no shared signals visible to us. Add the "shared_pending.signal & ~blocked" check. We don't use tsk->blocked directly but pass ~blocked as an argument, this is needed for the next patch. Note: we can optimize this more. while_each_thread(t) can check t->blocked into account and stop after every pending signal has the new target, see the next patch. Signed-off-by: Oleg Nesterov Reviewed-by: Matt Fleming Acked-by: Tejun Heo --- kernel/signal.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'kernel/signal.c') diff --git a/kernel/signal.c b/kernel/signal.c index 5341e2141904..06214b55dc5e 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2203,10 +2203,15 @@ relock: * group-wide signal. Another thread should be notified now to take * the signal since we will not. */ -static void retarget_shared_pending(struct task_struct *tsk) +static void retarget_shared_pending(struct task_struct *tsk, sigset_t *which) { + sigset_t retarget; struct task_struct *t; + sigandsets(&retarget, &tsk->signal->shared_pending.signal, which); + if (sigisemptyset(&retarget)) + return; + t = tsk; while_each_thread(tsk, t) { if (!signal_pending(t) && !(t->flags & PF_EXITING)) @@ -2217,6 +2222,7 @@ static void retarget_shared_pending(struct task_struct *tsk) void exit_signals(struct task_struct *tsk) { int group_stop = 0; + sigset_t unblocked; if (thread_group_empty(tsk) || signal_group_exit(tsk->signal)) { tsk->flags |= PF_EXITING; @@ -2232,7 +2238,9 @@ void exit_signals(struct task_struct *tsk) if (!signal_pending(tsk)) goto out; - retarget_shared_pending(tsk); + unblocked = tsk->blocked; + signotset(&unblocked); + retarget_shared_pending(tsk, &unblocked); if (unlikely(tsk->group_stop & GROUP_STOP_PENDING) && task_participate_group_stop(tsk)) -- cgit v1.2.3