From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756381Ab3LaQi4 (ORCPT ); Tue, 31 Dec 2013 11:38:56 -0500 Received: from merlin.infradead.org ([205.233.59.134]:49114 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753855Ab3LaQiy (ORCPT ); Tue, 31 Dec 2013 11:38:54 -0500 Date: Tue, 31 Dec 2013 09:38:51 -0700 From: Jens Axboe To: Ming Lei Cc: linux-kernel@vger.kernel.org, Christoph Hellwig Subject: Re: [PATCH v1 1/5] block: blk-mq: avoid initializing request during its completion Message-ID: <20131231163851.GJ21823@kernel.dk> References: <1388064698-27344-1-git-send-email-tom.leiming@gmail.com> <1388064698-27344-2-git-send-email-tom.leiming@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1388064698-27344-2-git-send-email-tom.leiming@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 26 2013, Ming Lei wrote: > One problem is that request->start_time/start_time_ns could be > set as wrong. > > Also it is normal to intialize one data structure just after its > allocation. > > So move the initialization out of its completion path. It's done that way because of presumed cache hotness on completion, since we just touched a lot of the members. Lets just fix the start time issue by itself. -- Jens Axboe