Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753496AbaBYU7h (ORCPT ); Tue, 25 Feb 2014 15:59:37 -0500 Received: from forward7l.mail.yandex.net ([84.201.143.140]:35544 "EHLO forward7l.mail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752635AbaBYU7g (ORCPT ); Tue, 25 Feb 2014 15:59:36 -0500 X-Yandex-Uniq: 757c79e5-2eb6-4b7b-885a-25a5a4f5b11a Authentication-Results: smtp17.mail.yandex.net; dkim=pass header.i=@yandex.ru Message-ID: <1393361805.12438.6.camel@HP-250-G1-Notebook-PC> Subject: Re: [PATCH] sched/rt: fix rt timer activation/deactivation From: Kirill Tkhai Reply-To: tkhai@yandex.ru To: Juri Lelli Cc: mingo@redhat.com, peterz@infradead.org, linux-kernel@vger.kernel.org Date: Wed, 26 Feb 2014 00:56:45 +0400 In-Reply-To: <1393344328-16653-1-git-send-email-juri.lelli@gmail.com> References: <1393344328-16653-1-git-send-email-juri.lelli@gmail.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.8.5-2+b1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Вт, 2014-02-25 at 17:05 +0100, Juri Lelli wrote: > Destroy rt bandwidth timer when rq has no more RT tasks, even when > CONFIG_RT_GROUP_SCHED is not set. > > Signed-off-by: Juri Lelli > --- > kernel/sched/rt.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c > index a2740b7..7dba25a 100644 > --- a/kernel/sched/rt.c > +++ b/kernel/sched/rt.c > @@ -86,12 +86,12 @@ void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) > raw_spin_lock_init(&rt_rq->rt_runtime_lock); > } > > -#ifdef CONFIG_RT_GROUP_SCHED > static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) > { > hrtimer_cancel(&rt_b->rt_period_timer); > } > > +#ifdef CONFIG_RT_GROUP_SCHED > #define rt_entity_is_task(rt_se) (!(rt_se)->my_q) > > static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) > @@ -1011,8 +1011,12 @@ inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) > start_rt_bandwidth(&def_rt_bandwidth); > } > > -static inline > -void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {} > +static void > +dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) > +{ > + if (!rt_rq->rt_nr_running) > + destroy_rt_bandwidth(&def_rt_bandwidth); > +} The problem is bandwidth timer is not per-cpu. It's only for all processors from the span (sched_rt_period_mask()). Other CPUs may have enqueued RT tasks. So, it's not possible to do this. > > #endif /* CONFIG_RT_GROUP_SCHED */ > -- 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/