From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758942Ab2IKSqA (ORCPT ); Tue, 11 Sep 2012 14:46:00 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:64270 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753509Ab2IKSp6 (ORCPT ); Tue, 11 Sep 2012 14:45:58 -0400 Date: Tue, 11 Sep 2012 11:45:53 -0700 From: Tejun Heo To: Muthu Kumar Cc: Kent Overstreet , linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, axboe@kernel.dk, Vivek Goyal , Mikulas Patocka , bharrosh@panasas.com, david@fromorbit.com Subject: Re: [PATCH 2/2] block: Avoid deadlocks with bio allocation by stacking drivers Message-ID: <20120911184553.GT7677@google.com> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Tue, Sep 11, 2012 at 11:36:28AM -0700, Muthu Kumar wrote: > Does this preserve the CPU from which the bio was submitted > originally. Not familiar with cmwq, may be Tejun can clarify. > > Tejun - the question is, do we honor the rq_affinity with the above > rescue worker implementation? The work item would run from the same CPU but there isn't any mechanism to keep track of the issuing CPU if there are multiple bios to be rescued. Isn't rq_affinity an optimization hint? If so, I don't think it matters here. Thanks. -- tejun