Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758373Ab1CCP3b (ORCPT ); Thu, 3 Mar 2011 10:29:31 -0500 Received: from mail-px0-f174.google.com ([209.85.212.174]:32839 "EHLO mail-px0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753051Ab1CCP3a convert rfc822-to-8bit (ORCPT ); Thu, 3 Mar 2011 10:29:30 -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=c2hrDAByTTVO3BHfrEpQOwrdUVyFBFN4GqouaMXCjj5JQ20QDwCN1NfklxUVM6Hftq Jjmcpy3bBW1RKE3DchJX0XUHQNVIpXEHExKy3o2hdco9mB792KaP+QtlSBG7lfPanr9v /iBc9TFxUQTh+sY4vFfCSBYpdYTxM3OATOIyA= MIME-Version: 1.0 In-Reply-To: <20110303140551.GA20677@zhy> References: <20110303113435.GA2868@balbir.in.ibm.com> <20110303140551.GA20677@zhy> Date: Thu, 3 Mar 2011 20:59:29 +0530 X-Google-Sender-Auth: 183cH9ZnsCBV6VSMFzRVLAdHe5M 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: 1341 Lines: 36 On Thu, Mar 3, 2011 at 7:35 PM, Yong Zhang wrote: > On Thu, Mar 03, 2011 at 05:04:35PM +0530, Balbir Singh wrote: >> Fix hierarchical scheduling in sched rt group >> >> From: Balbir Singh >> >> The current sched rt code is broken when it comes to hierarchical >> scheduling, this patch fixes two problems >> >> 1. It adds redundant enqueuing (harmless) when it finds a queue >> ? ?has tasks enqueued, but it has no run time and it is not >> ? ?throttled. > > You say redundant here, so in fact we don't need it, right? > No, not really :) It is required, it is a backup check to see if we have queued tasks, rt_time of 0 and the runqueue is not throttled, why should it be dequeued? >> 2. The most important change is in sched_rt_rq_enqueue/dequeue. >> ? ?The code just picks the rt_rq belonging to the current cpu >> ? ?on which the period timer runs, the patch fixes it, so that >> ? ?the correct rt_se is enqueued/dequeued. > > Ah, this is true. It is also needed for stable-2.6.33+ > Yep, we'll need backports to stable versions 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/