From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261861AbVEWHyH (ORCPT ); Mon, 23 May 2005 03:54:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261867AbVEWHyH (ORCPT ); Mon, 23 May 2005 03:54:07 -0400 Received: from mx2.elte.hu ([157.181.151.9]:34181 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S261861AbVEWHyB (ORCPT ); Mon, 23 May 2005 03:54:01 -0400 Date: Mon, 23 May 2005 09:53:36 +0200 From: Ingo Molnar To: Steven Rostedt Cc: Alan Cox , dwalker@mvista.com, Linus Torvalds , kus Kusche Klaus , Linux Kernel Mailing List Subject: Re: Why yield in coredump_wait? [was: Re: Resent: BUG in RT 45-01 when RT program dumps core] Message-ID: <20050523075336.GA9287@elte.hu> References: <1116503763.15866.9.camel@localhost.localdomain> <1116509820.15866.28.camel@localhost.localdomain> <1116523552.14229.64.camel@dhcp153.mvista.com> <1116524583.21388.299.camel@localhost.localdomain> <1116525953.4097.15.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1116525953.4097.15.camel@localhost.localdomain> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Steven Rostedt wrote: > On Thu, 2005-05-19 at 18:43 +0100, Alan Cox wrote: > > On Iau, 2005-05-19 at 18:25, Daniel Walker wrote: > > > I've seen a RT yield warning on this yield while running the FUSYN > > > tests .. I can't imagine why it's there either. > > > > Would it not make more sense to kick a task out of hard real time at the > > point it begins dumping core. The core dumping sequence was never > > something that thread intended to execute at real time priority > > > > That's what I recommended in an earlier email. I figured I'd wait to > see Ingo's response before sending him any patches. The drop from RT > should probably be after the zap_threads, that way it can kill those > using the same mm right away. Which also goes to say, we should get > rid of that yield. i think the yield() is bogus - all of coredumping is (or ought to be) fully event-driven. I agree that coredumping itself does not need to run with RT priorities - but this does not change the fact that no kernel code should break if executing with RT priority. In my tree i removed one yield() from exec.c and changed the other one to msleep(1). Ingo