From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758923AbYJMO4S (ORCPT ); Mon, 13 Oct 2008 10:56:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753840AbYJMO4F (ORCPT ); Mon, 13 Oct 2008 10:56:05 -0400 Received: from casper.infradead.org ([85.118.1.10]:41575 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753534AbYJMO4D (ORCPT ); Mon, 13 Oct 2008 10:56:03 -0400 Date: Mon, 13 Oct 2008 10:55:59 -0400 From: Arjan van de Ven To: Linus Torvalds Cc: Karel Zak , Andrew Morton , Linux Kernel Mailing List , Nick Piggin , Ingo Molnar Subject: Re: [kerneloops] regression in 2.6.27 wrt "lock_page" and the "hwclock" program Message-ID: <20081013105559.15ccb67f@infradead.org> In-Reply-To: References: <20081004174433.14a5e093@infradead.org> <20081004215225.2444d54b.akpm@linux-foundation.org> <20081005081145.30ba921b@infradead.org> <20081005102742.de8353b4.akpm@linux-foundation.org> <20081005103826.6771540a@infradead.org> <20081012200004.GI10429@nb.net.home> Organization: Intel X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.12; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 12 Oct 2008 13:16:12 -0700 (PDT) Linus Torvalds wrote: > > > On Sun, 12 Oct 2008, Karel Zak wrote: > > > > Any suggestion how to nicely implement "don't schedule me out"? > > There's nothing you can do. If you take a page fault, you're done. > Forget about any "can't schedule" or "don't enable interrupts". The > kernel _has_ to handle the page fault, and that may involve IO and > thus random pauses. No ifs, buts or maybe's about it. > > This patch may or may not get rid of the warning, at least. It won't > fix hwclock, but that's apparently unfixable from the kernel - the > thing is just plain buggy. it almost sounds like it's trying to do something that ... really the kernel should be doing. Karel: Can you describe what it WANTS to do so we can see if we can just extend the linux kernel to do that the right way? -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org