Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755164AbaBULjN (ORCPT ); Fri, 21 Feb 2014 06:39:13 -0500 Received: from forward11.mail.yandex.net ([95.108.130.93]:53251 "EHLO forward11.mail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754825AbaBULjM (ORCPT ); Fri, 21 Feb 2014 06:39:12 -0500 X-Greylist: delayed 327 seconds by postgrey-1.27 at vger.kernel.org; Fri, 21 Feb 2014 06:39:12 EST From: Kirill Tkhai To: Peter Zijlstra Cc: "linux-kernel@vger.kernel.org" , Juri Lelli , Steven Rostedt , Ingo Molnar In-Reply-To: <20140221103715.GP9987@twins.programming.kicks-ass.net> References: <230991392848160@web13m.yandex.ru> <20140221103715.GP9987@twins.programming.kicks-ass.net> Subject: Re: [RFC] sched/deadline: Prevent rt_time growth to infinity MIME-Version: 1.0 Message-Id: <128831392982418@web15j.yandex.ru> X-Mailer: Yamail [ http://yandex.ru ] 5.0 Date: Fri, 21 Feb 2014 15:33:38 +0400 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=koi8-r Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 21.02.2014, 14:37, "Peter Zijlstra" : > On Thu, Feb 20, 2014 at 02:16:00AM +0400, Kirill Tkhai wrote: > >> ?Since deadline tasks share rt bandwidth, we must care about >> ?bandwidth timer set. Otherwise rt_time may grow up to infinity >> ?in update_curr_dl(), if there are no other available RT tasks >> ?on top level bandwidth. >> >> ?I'm going to decide the problem the way below. Almost untested >> ?because of I skipped almost all of recent patches which haveto be applied from lkml. >> >> ?Please say, if I skipped anything in idea. Maybe better put >> ?start_top_rt_bandwidth() into set_curr_task_dl()? > > How about we only increment rt_time when there's an RT bandwidth timer > active? This case RT and DL may eat all the time: -------------- time ------------------> |RT's working |DL's working| ---------------------------- |rt_runtime | | ---------------------------- | rt_period | Or at least more, than it's allowed. It looks like, if we want to limit time of high priority classes execution, we have to set the timer anyway. > --- > --- a/kernel/sched/rt.c > +++ b/kernel/sched/rt.c > @@ -568,6 +568,12 @@ static inline struct rt_bandwidth *sched [snipped by dumb mail client] -- 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/