Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754189Ab1DRNpv (ORCPT ); Mon, 18 Apr 2011 09:45:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:23014 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753745Ab1DRNpp (ORCPT ); Mon, 18 Apr 2011 09:45:45 -0400 Date: Mon, 18 Apr 2011 15:45:01 +0200 From: Oleg Nesterov To: Tejun Heo , Linus Torvalds , Andrew Morton Cc: "Nikita V. Youshchenko" , Matt Fleming , linux-kernel@vger.kernel.org Subject: [PATCH v2 2/7] signal: retarget_shared_pending: consider shared/unblocked signals only Message-ID: <20110418134501.GC15951@redhat.com> References: <20110418134421.GA15951@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110418134421.GA15951@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2167 Lines: 61 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 --- kernel/signal.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- sigprocmask/kernel/signal.c~2_optimize_retarget 2011-04-17 21:02:59.000000000 +0200 +++ sigprocmask/kernel/signal.c 2011-04-17 21:08:05.000000000 +0200 @@ -2022,10 +2022,15 @@ 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 *set) { + sigset_t shared_pending; struct task_struct *t; + sigandsets(&shared_pending, &tsk->signal->shared_pending.signal, set); + if (sigisemptyset(&shared_pending)) + return; + t = tsk; while_each_thread(tsk, t) { if (!signal_pending(t) && !(t->flags & PF_EXITING)) @@ -2036,6 +2041,7 @@ static void retarget_shared_pending(stru void exit_signals(struct task_struct *tsk) { int group_stop = 0; + sigset_t set; if (thread_group_empty(tsk) || signal_group_exit(tsk->signal)) { tsk->flags |= PF_EXITING; @@ -2051,7 +2057,9 @@ void exit_signals(struct task_struct *ts if (!signal_pending(tsk)) goto out; - retarget_shared_pending(tsk); + set = tsk->blocked; + signotset(&set); + retarget_shared_pending(tsk, &set); if (unlikely(tsk->signal->group_stop_count) && !--tsk->signal->group_stop_count) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/