Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759329Ab1CDI7L (ORCPT ); Fri, 4 Mar 2011 03:59:11 -0500 Received: from mail-px0-f174.google.com ([209.85.212.174]:47284 "EHLO mail-px0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755637Ab1CDI7J convert rfc822-to-8bit (ORCPT ); Fri, 4 Mar 2011 03:59:09 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=JKys5E907BqviyRkXeZtdvFHiSZpt3Vcd9oR1RROX8dTBPReX0suL7A4/2uX9h5dra oLAkgpnKLFRsGflLxHUqau6Ca4/YQbtIHgjBNpdLPzK375+XQ4Tajg+ZFonDkR6ROs1a lHHFgZUigErnw4lK6m/tO3j4lIfoo/CKor82g= MIME-Version: 1.0 In-Reply-To: References: <20110303113435.GA2868@balbir.in.ibm.com> <20110303140551.GA20677@zhy> <20110304072517.GC2868@balbir.in.ibm.com> Date: Fri, 4 Mar 2011 14:29:08 +0530 X-Google-Sender-Auth: 0Qy8l_Wf-DNFdMIQXKazClS7bFQ Message-ID: Subject: Re: [BUGFIX][PATCH] Fix sched rt group scheduling when hierachy is enabled From: Balbir Singh To: Yong Zhang Cc: "linux-kernel@vger.kernel.org" , Ingo Molnar , Peter Zijlstra , Srivatsa Vaddagiri , Bharata B Rao Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1183 Lines: 34 >>> ?deactivate_task(b); /* A.throttled == 1 && A.rt_nr_running == 0 */ >>> ? ?do_sched_rt_period_timer(); /* A.run_time == 0 && A.throttled == 0*/ >> >> Note at some point rt_time becomes 0 and if enqueue is not set, the > > If the group should be add back, it will be at the first > do_sched_rt_period_timer() which decreases run_time; > As long as idle is 0, the period will continue to run, if it has rt_nr_running or rt_time, the timer will run. >> next do_sched_rt_period_timer() is a NOP and does not enqueue back the >> group > > Otherwise it will be added back when a task is attching to it. > > I still can't see how a unthrottled group which has task attched stay > unqueued. The other way of looking at the first change is Can we have rt_time as 0, rt_nr_running >=1, rt_throttled !=0 and still not have the rt_rq enqueued? If this is not the case, we don't lose much, a quick check for rt_nr_running and on_rt_q Balbir -- 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/