From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755872AbYJZTdW (ORCPT ); Sun, 26 Oct 2008 15:33:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752743AbYJZTdN (ORCPT ); Sun, 26 Oct 2008 15:33:13 -0400 Received: from casper.infradead.org ([85.118.1.10]:49183 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753227AbYJZTdM (ORCPT ); Sun, 26 Oct 2008 15:33:12 -0400 Date: Sun, 26 Oct 2008 12:33:32 -0700 From: Arjan van de Ven To: Linus Torvalds Cc: Linux Kernel Mailing List , "Rafael J. Wysocki" , davidel@xmailserver.org, Thomas Gleixner Subject: Re: kerneloops.org: 2.6.28-rc regression in epoll (list corruption) Message-ID: <20081026123332.10a1941f@infradead.org> In-Reply-To: References: <20081026112920.28e7dccc@infradead.org> 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, 26 Oct 2008 11:58:06 -0700 (PDT) Linus Torvalds wrote: > > > On Sun, 26 Oct 2008, Arjan van de Ven wrote: > > > > This one is upcoming fast (and I just hit it as well) > > > > http://www.kerneloops.org/searchweek.php?search=ep_poll_callback > > > > seems epoll grew some list corruption.... > > It sounds very much like f337b9c58332bdecde965b436e47ea4c94d30da0 > ("epoll: drop unnecessary test") deleted a test that wasn't so > unnecessary after all.. > > That ep_poll_callback() code is: > > /* If this file is already in the ready list we exit soon */ > if (ep_is_linked(&epi->rdllink)) > goto is_linked; > > list_add_tail(&epi->rdllink, &ep->rdllist); > > and the unnecessary test that was removed looks _very_ much like that > kind of code. > > Thomas? Davide? > > And if somebody knows how to reproduce this reliably, it would be > really good to hear if doing a revert on that thing just fixed it. It > should revert cleanly - it's the only change to fs/eventpoll.c since > 2.6.27. > I did the revert and did the same thing I did before, and haven't seen it yet. (this is obviously a really small sample size on both sides of the line, but it's at least not show it easily now while I saw it a few times before.. after I fixed my Wifi and manually set the r8169 mac) -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org