From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755247AbZESIwP (ORCPT ); Tue, 19 May 2009 04:52:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751265AbZESIwG (ORCPT ); Tue, 19 May 2009 04:52:06 -0400 Received: from xc.sipsolutions.net ([83.246.72.84]:57702 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751212AbZESIwG (ORCPT ); Tue, 19 May 2009 04:52:06 -0400 Subject: Re: INFO: possible circular locking dependency at cleanup_workqueue_thread From: Johannes Berg To: Oleg Nesterov Cc: Ingo Molnar , Zdenek Kabelac , "Rafael J. Wysocki" , Peter Zijlstra , Linux Kernel Mailing List In-Reply-To: <20090518194749.GA3501@redhat.com> References: <20090517071834.GA8507@elte.hu> <1242559101.28127.63.camel@johannes.local> <20090518194749.GA3501@redhat.com> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-E+brN6AtQyTxeMkrhYUU" Date: Tue, 19 May 2009 10:51:44 +0200 Message-Id: <1242723104.17164.5.camel@johannes.local> Mime-Version: 1.0 X-Mailer: Evolution 2.26.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-E+brN6AtQyTxeMkrhYUU Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Mon, 2009-05-18 at 21:47 +0200, Oleg Nesterov wrote: > > Maybe it shouldn't do that from the CPU_POST_DEAD > > notifier? >=20 > Well, in any case we should understand why we have the problem, before > changing the code. And CPU_POST_DEAD is not special, why should we treat > it specially and skip lock_map_acquire(wq->lockdep_map) ? I'm not familiar enough with the code -- but what are we really trying to do in CPU_POST_DEAD? It seems to me that at that time things must already be off the CPU, so ...? On the other hand that calls flush_cpu_workqueue() so it seems it would actually wait for the work to be executed on some other CPU, within the CPU_POST_DEAD notification? johannes --=-E+brN6AtQyTxeMkrhYUU Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- iQIcBAABAgAGBQJKEnMdAAoJEODzc/N7+QmaVW0P/0YfH/YGtoreKBgqEFmo6wqW iamLMiTsc+7C7/AD25yOPubjISV1BVLgJd3qi4moOnLMv7mK8G4ULS2Wz0FkNHgM i1fIgJbuwNuigvsBSqt0s07XG0W2lqxHfF8YZsAk8AvYeVzWKhIqTNBPpZQD7d0W Ck8XtKTDDakY/1RDzg2NKlKb288BwanftzbjH4V1PJvZkzxPcVLUOCUrbY68AC5L 9q6gSYk/ZO6znLqtkFT5Yrm+BchNZZk1fxaKpX9DtwVAaGYOAMQ8tieMzeOYXmV5 3n6n+C4TPqyKspyFbRVS+W/OmuhhD4ZlrbnA6TOOyQUxrH5EI4qrnY98z2/j5lOv Qns331+DMjzfgkPp35xZNoal4oFaIsHIL6slKiotK4Tt3b8d+/CMvkIqJlSy2A4n Ck8x5oaoM9JhwxhkQViC4GQS616QMhjqa+GtlKMDHDmj+PIgwXoftoPsSo0GMxMI xnRqzB77Lk8C+AWLgW+O2DCd4xPXXugD2hExeE5je2xomJN3sYjyz9EgDwZk8GyA WYnnZKaoLmg+dSbCXn38f4wCWPpO7+3fWDnmfznqsHChPH7VFV4g/oVMRU3VHvQO wls+YkQ1w9nAX0GJeu8x71nAosFXLCb46T0Rgz2ZUPCFTGejaHETMoEThZJjkLDc 2h/cKX6T0ni/OjH57iJf =7p/P -----END PGP SIGNATURE----- --=-E+brN6AtQyTxeMkrhYUU--