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| author | Oleg Nesterov <oleg@redhat.com> | 2011-04-27 19:18:39 +0200 |
|---|---|---|
| committer | Oleg Nesterov <oleg@redhat.com> | 2011-04-28 13:01:35 +0200 |
| commit | f646e227b88a164a841d6b6dd969d8a45272dd83 (patch) | |
| tree | bd11235d720e384efc20e01f116bbf904ca58b4f /kernel/signal.c | |
| parent | 0edceb7bcd82802f721f3c94eed9b3e2869d3740 (diff) | |
| download | lwn-f646e227b88a164a841d6b6dd969d8a45272dd83.tar.gz lwn-f646e227b88a164a841d6b6dd969d8a45272dd83.zip | |
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 <oleg@redhat.com>
Reviewed-by: Matt Fleming <matt.fleming@linux.intel.com>
Acked-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 12 |
1 files changed, 10 insertions, 2 deletions
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)) |