Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932737Ab1ERCHX (ORCPT ); Tue, 17 May 2011 22:07:23 -0400 Received: from mail-gx0-f174.google.com ([209.85.161.174]:42262 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932657Ab1ERCHW (ORCPT ); Tue, 17 May 2011 22:07:22 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=dD0L3qjqB6jIWlELAumJmeIByT1SCowN1AEDWn1LRr/ihBVV5N5Q9MMMyXnN5CprPs si3COXHb0FdpQoOawZVcOQrET3okmNwdrXfvmvFsHX0pOCOSkmX4mQbAJmuVpriI7Atz 2p52nDNALvBbW2CwNk9w80xP2qXxHKBCPcAeo= MIME-Version: 1.0 In-Reply-To: References: Date: Wed, 18 May 2011 10:07:21 +0800 Message-ID: Subject: Re: [PATCH] sched: fix priority leakage in pick_next_highest_task_rt() From: Yong Zhang To: Hillf Danton Cc: LKML , Ingo Molnar , Peter Zijlstra , Mike Galbraith Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1125 Lines: 33 On Tue, May 17, 2011 at 10:53 PM, Hillf Danton wrote: > On Tue, May 17, 2011 at 10:28 AM, Yong Zhang wrote: >> On Mon, May 16, 2011 at 8:55 PM, Hillf Danton wrote: >>> When picking the second highest RT task for a given runqueue, if no >>> task found after scanning the queue of priority == idx, the next idx >>> should also be checked even in case that next is already existing, or >>> the window of priority leakage could be opened. >> >> I don't see what kind of problem you patch will fix. >> And mind explaining how priority leakage could happen? >> > Hi Yong > > If no task is found after scanning the list at array->queue + idx, > what should we operate on next? > And why is the list scanned? Hmmm, I get your point. Reviewed-by: Yong Zhang Thanks, Yong -- Only stand for myself -- 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/