From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758412Ab2CAMTm (ORCPT ); Thu, 1 Mar 2012 07:19:42 -0500 Received: from terminus.zytor.com ([198.137.202.10]:37513 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753953Ab2CAMTl (ORCPT ); Thu, 1 Mar 2012 07:19:41 -0500 Date: Thu, 1 Mar 2012 04:19:06 -0800 From: tip-bot for Thomas Gleixner Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@elte.hu To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/rt: Document scheduler related skip-resched-check sites Git-Commit-ID: ba74c1448f127649046615ec017bded7b2a76f29 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (terminus.zytor.com [127.0.0.1]); Thu, 01 Mar 2012 04:19:33 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: ba74c1448f127649046615ec017bded7b2a76f29 Gitweb: http://git.kernel.org/tip/ba74c1448f127649046615ec017bded7b2a76f29 Author: Thomas Gleixner AuthorDate: Mon, 21 Mar 2011 13:32:17 +0100 Committer: Ingo Molnar CommitDate: Thu, 1 Mar 2012 10:28:04 +0100 sched/rt: Document scheduler related skip-resched-check sites Create a distinction between scheduler related preempt_enable_no_resched() calls and the nearly one hundred other places in the kernel that do not want to reschedule, for one reason or another. This distinction matters for -rt, where the scheduler and the non-scheduler preempt models (and checks) are different. For upstream it's purely documentational. Signed-off-by: Thomas Gleixner Link: http://lkml.kernel.org/n/tip-gs88fvx2mdv5psnzxnv575ke@git.kernel.org Signed-off-by: Ingo Molnar --- arch/powerpc/kernel/idle.c | 2 +- arch/sparc/kernel/process_64.c | 2 +- include/linux/preempt.h | 5 ++++- kernel/sched/core.c | 6 +++--- kernel/softirq.c | 4 ++-- 5 files changed, 11 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c index 6503514..c97fc60 100644 --- a/arch/powerpc/kernel/idle.c +++ b/arch/powerpc/kernel/idle.c @@ -102,7 +102,7 @@ void cpu_idle(void) rcu_idle_exit(); tick_nohz_idle_exit(); if (cpu_should_die()) { - preempt_enable_no_resched(); + sched_preempt_enable_no_resched(); cpu_die(); } schedule_preempt_disabled(); diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c index ab9a292..06b5b5f 100644 --- a/arch/sparc/kernel/process_64.c +++ b/arch/sparc/kernel/process_64.c @@ -106,7 +106,7 @@ void cpu_idle(void) #ifdef CONFIG_HOTPLUG_CPU if (cpu_is_offline(cpu)) { - preempt_enable_no_resched(); + sched_preempt_enable_no_resched(); cpu_play_dead(); } #endif diff --git a/include/linux/preempt.h b/include/linux/preempt.h index 58969b2..5a710b9 100644 --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -48,12 +48,14 @@ do { \ barrier(); \ } while (0) -#define preempt_enable_no_resched() \ +#define sched_preempt_enable_no_resched() \ do { \ barrier(); \ dec_preempt_count(); \ } while (0) +#define preempt_enable_no_resched() sched_preempt_enable_no_resched() + #define preempt_enable() \ do { \ preempt_enable_no_resched(); \ @@ -92,6 +94,7 @@ do { \ #else /* !CONFIG_PREEMPT_COUNT */ #define preempt_disable() do { } while (0) +#define sched_preempt_enable_no_resched() do { } while (0) #define preempt_enable_no_resched() do { } while (0) #define preempt_enable() do { } while (0) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 7302239..643cc37 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3220,7 +3220,7 @@ need_resched: post_schedule(rq); - preempt_enable_no_resched(); + sched_preempt_enable_no_resched(); if (need_resched()) goto need_resched; } @@ -3253,7 +3253,7 @@ EXPORT_SYMBOL(schedule); */ void __sched schedule_preempt_disabled(void) { - preempt_enable_no_resched(); + sched_preempt_enable_no_resched(); schedule(); preempt_disable(); } @@ -4486,7 +4486,7 @@ SYSCALL_DEFINE0(sched_yield) __release(rq->lock); spin_release(&rq->lock.dep_map, 1, _THIS_IP_); do_raw_spin_unlock(&rq->lock); - preempt_enable_no_resched(); + sched_preempt_enable_no_resched(); schedule(); diff --git a/kernel/softirq.c b/kernel/softirq.c index 79b5247..f268369 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -353,7 +353,7 @@ void irq_exit(void) tick_nohz_irq_exit(); #endif rcu_irq_exit(); - preempt_enable_no_resched(); + sched_preempt_enable_no_resched(); } /* @@ -759,7 +759,7 @@ static int run_ksoftirqd(void * __bind_cpu) if (local_softirq_pending()) __do_softirq(); local_irq_enable(); - preempt_enable_no_resched(); + sched_preempt_enable_no_resched(); cond_resched(); preempt_disable(); rcu_note_context_switch((long)__bind_cpu);