From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753224Ab2L1KBe (ORCPT ); Fri, 28 Dec 2012 05:01:34 -0500 Received: from na3sys009aog134.obsmtp.com ([74.125.149.83]:59937 "EHLO na3sys009aog134.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753156Ab2L1KBa (ORCPT ); Fri, 28 Dec 2012 05:01:30 -0500 From: Neil Zhang To: mingo@kernel.org, peterz@infradead.org Cc: linux-kernel@vger.kernel.org, Neil Zhang , bitbucket@online.de Subject: [PATCH] sched: remove redundant update_runtime notifier Date: Fri, 28 Dec 2012 18:00:26 +0800 Message-Id: <1356688826-23158-1-git-send-email-zhangwm@marvell.com> X-Mailer: git-send-email 1.7.4.1 X-OriginalArrivalTime: 28 Dec 2012 10:00:41.0850 (UTC) FILETIME=[3222DDA0:01CDE4E2] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org migration_call() will do all the things that update_runtime() does. So it seems update_runtime() is a redundant notifier, remove it. Furthermore, there is potential risk that the current code will catch BUG_ON at line 687 of rt.c when do cpu hotplug while there are realtime threads running because of enable runtime twice. Cc: bitbucket@online.de Signed-off-by: Neil Zhang --- kernel/sched/core.c | 3 --- kernel/sched/rt.c | 40 ---------------------------------------- kernel/sched/sched.h | 1 - 3 files changed, 0 insertions(+), 44 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 257002c..7b6a4d8 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6779,9 +6779,6 @@ void __init sched_init_smp(void) hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE); hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE); - /* RT runtime code needs to handle some hotplug events */ - hotcpu_notifier(update_runtime, 0); - init_hrtick(); /* Move init over to a non-isolated CPU */ diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 418feb0..1a499d2 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -697,15 +697,6 @@ balanced: } } -static void disable_runtime(struct rq *rq) -{ - unsigned long flags; - - raw_spin_lock_irqsave(&rq->lock, flags); - __disable_runtime(rq); - raw_spin_unlock_irqrestore(&rq->lock, flags); -} - static void __enable_runtime(struct rq *rq) { rt_rq_iter_t iter; @@ -730,37 +721,6 @@ static void __enable_runtime(struct rq *rq) } } -static void enable_runtime(struct rq *rq) -{ - unsigned long flags; - - raw_spin_lock_irqsave(&rq->lock, flags); - __enable_runtime(rq); - raw_spin_unlock_irqrestore(&rq->lock, flags); -} - -int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu) -{ - int cpu = (int)(long)hcpu; - - switch (action) { - case CPU_DOWN_PREPARE: - case CPU_DOWN_PREPARE_FROZEN: - disable_runtime(cpu_rq(cpu)); - return NOTIFY_OK; - - case CPU_DOWN_FAILED: - case CPU_DOWN_FAILED_FROZEN: - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - enable_runtime(cpu_rq(cpu)); - return NOTIFY_OK; - - default: - return NOTIFY_DONE; - } -} - static int balance_runtime(struct rt_rq *rt_rq) { int more = 0; diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index fc88644..16d18a1 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -890,7 +890,6 @@ extern void sysrq_sched_debug_show(void); extern void sched_init_granularity(void); extern void update_max_interval(void); extern void update_group_power(struct sched_domain *sd, int cpu); -extern int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu); extern void init_sched_rt_class(void); extern void init_sched_fair_class(void); -- 1.7.4.1