From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicholas Mc Guire Subject: [PATCH] allow preemption in recursive migrate_disable call Date: Wed, 20 Nov 2013 01:33:33 +0100 Message-ID: <20131120003333.GA13545@opentech.at> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Peter Zijlstra , Thomas Gleixner , Andreas Platschek To: linux-rt-users@vger.kernel.org Return-path: Received: from hofr.at ([212.69.189.236]:47675 "EHLO mail.hofr.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753422Ab3KTAld (ORCPT ); Tue, 19 Nov 2013 19:41:33 -0500 Content-Disposition: inline Sender: linux-rt-users-owner@vger.kernel.org List-ID: >>From a7259c360b6c8b873f5fcf6d5eed0ae78534a6c5 Mon Sep 17 00:00:00 2001 From: Nicholas Mc Guire Date: Wed, 20 Nov 2013 07:22:09 +0800 Subject: [PATCH] allow preemption in recursive migrate_disable call Minor cleanup in migrate_disable/migrate_enable. The recursive case does not need to disable preemption as it is "pinned" to the current cpu any way so it is safe to preempt it. No functional change to migrate_disable/enable Signed-off-by: Nicholas Mc Guire --- kernel/sched/core.c | 6 ++---- 1 files changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index a7fafc28..22fa2e2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2418,13 +2418,12 @@ void migrate_disable(void) } #endif - preempt_disable(); if (p->migrate_disable) { p->migrate_disable++; - preempt_enable(); return; } + preempt_disable(); preempt_lazy_disable(); pin_current_cpu(); p->migrate_disable = 1; @@ -2454,13 +2453,12 @@ void migrate_enable(void) #endif WARN_ON_ONCE(p->migrate_disable <= 0); - preempt_disable(); if (migrate_disable_count(p) > 1) { p->migrate_disable--; - preempt_enable(); return; } + preempt_disable(); if (unlikely(migrate_disabled_updated(p))) { /* * Undo whatever update_migrate_disable() did, also see there -- 1.7.3.4