From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751686AbeCWH2L (ORCPT ); Fri, 23 Mar 2018 03:28:11 -0400 Received: from zimbra1.kalray.eu ([92.103.151.219]:59604 "EHLO zimbra1.kalray.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751288AbeCWH2J (ORCPT ); Fri, 23 Mar 2018 03:28:09 -0400 DKIM-Filter: OpenDKIM Filter v2.9.2 zimbra1.kalray.eu EE4AF2800BA Date: Fri, 23 Mar 2018 08:28:07 +0100 (CET) From: Marta Rybczynska To: Bjorn Helgaas Cc: Keith Busch , Ming Lei , axboe@fb.com, hch@lst.de, sagi@grimberg.me, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, bhelgaas@google.com, linux-pci@vger.kernel.org, Pierre-Yves Kerbrat , Srinath Mannam Message-ID: <2116255963.5924726.1521790087788.JavaMail.zimbra@kalray.eu> In-Reply-To: <20180321215308.GH38649@bhelgaas-glaptop.roam.corp.google.com> References: <744877924.5841545.1521630049567.JavaMail.zimbra@kalray.eu> <20180321115037.GA26083@ming.t460p> <464125757.5843583.1521634231341.JavaMail.zimbra@kalray.eu> <20180321154807.GD22254@ming.t460p> <20180321160238.GF12909@localhost.localdomain> <1220434088.5871933.1521648656789.JavaMail.zimbra@kalray.eu> <20180321215308.GH38649@bhelgaas-glaptop.roam.corp.google.com> Subject: Re: [RFC PATCH] nvme: avoid race-conditions when enabling devices MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.40.201] X-Mailer: Zimbra 8.6.0_GA_1182 (ZimbraWebClient - FF53 (Linux)/8.6.0_GA_1182) Thread-Topic: nvme: avoid race-conditions when enabling devices Thread-Index: HEm8VKpOsMNARqgalq8SCLBWZnhtLg== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Wed, Mar 21, 2018 at 05:10:56PM +0100, Marta Rybczynska wrote: >> >> The problem may happen also with other device doing its probe and >> nvme running its workqueue (and we probably have seen it in practice >> too). We were thinking about a lock in the pci generic code too, >> that's why I've put the linux-pci@ list in copy. > > Yes, this is a generic problem in the PCI core. We've tried to fix it > in the past but haven't figured it out yet. > > See 40f11adc7cd9 ("PCI: Avoid race while enabling upstream bridges") > and 0f50a49e3008 ("Revert "PCI: Avoid race while enabling upstream > bridges""). > > It's not trivial, but if you figure out a good way to fix this, I'd be > thrilled. > Bjorn, Srinath, are you aware of anyone working on an updated fix for this one? Marta