From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755721Ab2DSPeo (ORCPT ); Thu, 19 Apr 2012 11:34:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:30629 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755673Ab2DSPen (ORCPT ); Thu, 19 Apr 2012 11:34:43 -0400 Date: Thu, 19 Apr 2012 11:34:35 -0400 From: Jason Baron To: "Alexandra N. Kossovsky" Cc: Andrew Morton , Yurij.Plotnikov@oktetlabs.ru, davidel@xmailserver.org, nelhage@nelhage.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] epoll: clear the tfile_check_list on -ELOOP Message-ID: <20120419153428.GA1596@redhat.com> References: <201204171434.q3HEYqrq007242@int-mx09.intmail.prod.int.phx2.redhat.com> <20120417141315.703056a6.akpm@linux-foundation.org> <20120418045615.GU29100@oktetlabs.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120418045615.GU29100@oktetlabs.ru> User-Agent: Mutt/1.5.20 (2009-12-10) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 18, 2012 at 08:56:15AM +0400, Alexandra N. Kossovsky wrote: > On Tue, Apr 17, 2012 at 02:13:15PM -0700, Andrew Morton wrote: > > On Tue, 17 Apr 2012 10:34:52 -0400 > > Jason Baron wrote: > > > > > An epoll_ctl(,EPOLL_CTL_ADD,,) operation can return '-ELOOP' to prevent > > > circular epoll dependencies from being created. However, in that case > > > we do not properly clear the 'tfile_check_list'. Thus, add a call to > > > clear_tfile_check_list() for the -ELOOP case. > > > > So here I am wondering what effect this bug has upon our users, so I > > can decide which kernel versions should be fixed. Jason didn't tell me > > so I went to read the description of clear_tfile_check_list(). After a > > brief chuckle, I stopped. > > > > I then found Yurij's original report, so I know what's going on. But I > > still can't write your changelog because I don't know whether this is a > > regression and if it is, which patch caused the regression. > > It is a regression, somewhere between 3.2.6 and 3.2.9. > Yurij and me blame > commit 203aa5260edca2ab1872ad8b08386d874f7132f3 > Author: Jason Baron > Date: Thu Jan 12 17:17:43 2012 -0800 > but we have not tested it. > Right, I introduced this with the upstream commit: commit 28d82dc1c4edbc352129f97f4ca22624d1fe61de Author: Jason Baron Date: Thu Jan 12 17:17:43 2012 -0800 epoll: limit paths So yes, this is a newly introduced regression. Thanks, -Jason