From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757429Ab2IJWvN (ORCPT ); Mon, 10 Sep 2012 18:51:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46761 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752861Ab2IJWvL (ORCPT ); Mon, 10 Sep 2012 18:51:11 -0400 Date: Mon, 10 Sep 2012 23:50:57 +0100 From: Alasdair G Kergon To: Kent Overstreet , axboe@kernel.dk, device-mapper development , david@fromorbit.com, linux-kernel@vger.kernel.org, linux-bcache@vger.kernel.org, Mikulas Patocka , bharrosh@panasas.com, Vivek Goyal Subject: Re: [dm-devel] [PATCH 2/2] block: Avoid deadlocks with bio allocation by stacking drivers Message-ID: <20120910225057.GA10477@agk-dp.fab.redhat.com> Mail-Followup-To: Kent Overstreet , axboe@kernel.dk, device-mapper development , david@fromorbit.com, linux-kernel@vger.kernel.org, linux-bcache@vger.kernel.org, Mikulas Patocka , bharrosh@panasas.com, Vivek Goyal References: <1347055973-11581-3-git-send-email-koverstreet@google.com> <20120908193641.GB12773@dhcp-172-17-108-109.mtv.corp.google.com> <20120910002810.GA23241@moria.home.lan> <20120910172210.GC14103@google.com> <20120910202435.GG16360@google.com> <20120910204010.GA32310@google.com> <20120910213349.GH16360@google.com> <20120910213710.GA7677@google.com> <20120910215633.GA19739@google.com> <20120910220910.GB7677@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120910220910.GB7677@google.com> Organization: Red Hat UK Ltd. Registered in England and Wales, number 03798903. Registered Office: 64 Baker Street, 4th floor, London, W1U 7DF. User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 10, 2012 at 03:09:10PM -0700, Tejun Heo wrote: > On Mon, Sep 10, 2012 at 02:56:33PM -0700, Kent Overstreet wrote: > > commit df7e63cbffa3065fcc4ba2b9a93418d7c7312243 > > Author: Kent Overstreet > > Date: Mon Sep 10 14:33:46 2012 -0700 > > > > block: Avoid deadlocks with bio allocation by stacking drivers > > Note that this doesn't do anything for allocation from other mempools. Note that dm has several cases of this, so this patch should not be used with dm yet. Mikulas is studying those cases to see whether anything like this might be feasible/sensible or not. > I'm still a bit scared but think this is correct. > Acked-by: Tejun Heo Alasdair