From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761436Ab2DKXJ0 (ORCPT ); Wed, 11 Apr 2012 19:09:26 -0400 Received: from a.ns.miles-group.at ([95.130.255.143]:47834 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759089Ab2DKXJY (ORCPT ); Wed, 11 Apr 2012 19:09:24 -0400 Message-ID: <4F860F17.2090400@nod.at> Date: Thu, 12 Apr 2012 01:09:11 +0200 From: Richard Weinberger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120312 Thunderbird/11.0 MIME-Version: 1.0 To: Hugh Dickins CC: Konstantin Khlebnikov , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "paul.gortmaker@windriver.com" , Andrew Morton Subject: Re: swapoff() runs forever References: <4F81F564.3020904@nod.at> <4F82752A.6020206@openvz.org> <4F82B6ED.2010500@nod.at> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 09.04.2012 20:40, schrieb Hugh Dickins: > I've not seen any such issue in recent months (or years), but > I've not been using UML either. The most likely cause that springs > to mind would be corruption of the vmalloc'ed swap map: that would > be very likely to cause such a hang. It does not look like a swap map corruption. If I restart most user space processes swapoff() terminates fine. Maybe it is a refcounting problem? > You say "recent Linux kernels": I wonder what "recent" means. > Is this something you can reproduce quickly and reliably enough > to do a bisection upon? > I can reproduce the issue on any UML kernel. The oldest I've tested was 2.6.20. Therefore, bug was not introduced by me. B-) Thanks, //richard