From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266589AbTGFCOP (ORCPT ); Sat, 5 Jul 2003 22:14:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266592AbTGFCOO (ORCPT ); Sat, 5 Jul 2003 22:14:14 -0400 Received: from x35.xmailserver.org ([208.129.208.51]:62868 "EHLO x35.xmailserver.org") by vger.kernel.org with ESMTP id S266589AbTGFCOO (ORCPT ); Sat, 5 Jul 2003 22:14:14 -0400 X-AuthUser: davidel@xmailserver.org Date: Sat, 5 Jul 2003 19:21:02 -0700 (PDT) From: Davide Libenzi X-X-Sender: davide@bigblue.dev.mcafeelabs.com To: Daniel Phillips cc: Jamie Lokier , Andrew Morton , Linux Kernel Mailing List , linux-mm@kvack.org Subject: Re: 2.5.74-mm1 In-Reply-To: <200307060414.34827.phillips@arcor.de> Message-ID: References: <20030703023714.55d13934.akpm@osdl.org> <200307060010.26002.phillips@arcor.de> <20030706012857.GA29544@mail.jlokier.co.uk> <200307060414.34827.phillips@arcor.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 6 Jul 2003, Daniel Phillips wrote: > On Sunday 06 July 2003 03:28, Jamie Lokier wrote: > > > > Your last point is most important. At the moment, a SCHED_RR process > > with a bug will basically lock up the machine, which is totally > > inappropriate for a user app. > > How does the lockup come about? As defined, a single SCHED_RR process could > lock up only its own slice of CPU, as far as I can see. They're de-queued and re-queue in the active array w/out having dynamic priority adjustment (like POSIX states). This means that any task with lower priority will starve if the RR task will not release the CPU. - Davide