From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760627AbZDAL2V (ORCPT ); Wed, 1 Apr 2009 07:28:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754247AbZDAL2K (ORCPT ); Wed, 1 Apr 2009 07:28:10 -0400 Received: from hera.kernel.org ([140.211.167.34]:37641 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753935AbZDAL2J (ORCPT ); Wed, 1 Apr 2009 07:28:09 -0400 Date: Wed, 1 Apr 2009 11:27:27 GMT From: Rusty Russell To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, rusty@rustcorp.com.au, srostedt@redhat.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, rusty@rustcorp.com.au, srostedt@redhat.com, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <200903251501.22664.rusty@rustcorp.com.au> References: <200903251501.22664.rusty@rustcorp.com.au> Subject: [tip:sched/urgent] sched_rt: don't allocate cpumask in fastpath Message-ID: Git-Commit-ID: 13b8bd0a5713bdf05659019badd7c0407984ece1 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Wed, 01 Apr 2009 11:27:29 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 13b8bd0a5713bdf05659019badd7c0407984ece1 Gitweb: http://git.kernel.org/tip/13b8bd0a5713bdf05659019badd7c0407984ece1 Author: Rusty Russell AuthorDate: Wed, 25 Mar 2009 15:01:22 +1030 Committer: Ingo Molnar CommitDate: Wed, 1 Apr 2009 13:24:51 +0200 sched_rt: don't allocate cpumask in fastpath Impact: cleanup As pointed out by Steven Rostedt. Since the arg in question is unused, we simply change cpupri_find() to accept NULL. Reported-by: Steven Rostedt Signed-off-by: Rusty Russell LKML-Reference: <200903251501.22664.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar --- kernel/sched_cpupri.c | 5 +++-- kernel/sched_rt.c | 15 ++++----------- 2 files changed, 7 insertions(+), 13 deletions(-) diff --git a/kernel/sched_cpupri.c b/kernel/sched_cpupri.c index 1e00bfa..cdd3c89 100644 --- a/kernel/sched_cpupri.c +++ b/kernel/sched_cpupri.c @@ -55,7 +55,7 @@ static int convert_prio(int prio) * cpupri_find - find the best (lowest-pri) CPU in the system * @cp: The cpupri context * @p: The task - * @lowest_mask: A mask to fill in with selected CPUs + * @lowest_mask: A mask to fill in with selected CPUs (or NULL) * * Note: This function returns the recommended CPUs as calculated during the * current invokation. By the time the call returns, the CPUs may have in @@ -81,7 +81,8 @@ int cpupri_find(struct cpupri *cp, struct task_struct *p, if (cpumask_any_and(&p->cpus_allowed, vec->mask) >= nr_cpu_ids) continue; - cpumask_and(lowest_mask, &p->cpus_allowed, vec->mask); + if (lowest_mask) + cpumask_and(lowest_mask, &p->cpus_allowed, vec->mask); return 1; } diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index bac1061..fbec5a5 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -805,20 +805,15 @@ static int select_task_rq_rt(struct task_struct *p, int sync) static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) { - cpumask_var_t mask; - if (rq->curr->rt.nr_cpus_allowed == 1) return; - if (!alloc_cpumask_var(&mask, GFP_ATOMIC)) - return; - if (p->rt.nr_cpus_allowed != 1 - && cpupri_find(&rq->rd->cpupri, p, mask)) - goto free; + && cpupri_find(&rq->rd->cpupri, p, NULL)) + return; - if (!cpupri_find(&rq->rd->cpupri, rq->curr, mask)) - goto free; + if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL)) + return; /* * There appears to be other cpus that can accept @@ -827,8 +822,6 @@ static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) */ requeue_task_rt(rq, p, 1); resched_task(rq->curr); -free: - free_cpumask_var(mask); } #endif /* CONFIG_SMP */