From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753427AbdLMQJS (ORCPT ); Wed, 13 Dec 2017 11:09:18 -0500 Received: from mail-qt0-f182.google.com ([209.85.216.182]:36176 "EHLO mail-qt0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751026AbdLMQJQ (ORCPT ); Wed, 13 Dec 2017 11:09:16 -0500 X-Google-Smtp-Source: ACJfBoufbnIqitRtmrgmy9Ab46xDUkY6qt/Ez9ETFhVPDr5aKK/98DTtnd7wAr+7KObh3a/IKWYWcg== Date: Wed, 13 Dec 2017 08:09:13 -0800 From: Tejun Heo To: "jianchao.wang" Cc: axboe@kernel.dk, linux-kernel@vger.kernel.org, oleg@redhat.com, peterz@infradead.org, kernel-team@fb.com, osandov@fb.com Subject: Re: [PATCH 6/6] blk-mq: remove REQ_ATOM_STARTED Message-ID: <20171213160913.GR3919388@devbig577.frc2.facebook.com> References: <20171209192525.982030-1-tj@kernel.org> <20171209192525.982030-7-tj@kernel.org> <8c52269a-d5a9-d13c-bdb6-8f47cdaed982@oracle.com> <20171212172629.GF3919388@devbig577.frc2.facebook.com> <9e9452b1-5756-71fc-f7f9-2a90aceccf01@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9e9452b1-5756-71fc-f7f9-2a90aceccf01@oracle.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Wed, Dec 13, 2017 at 11:05:11AM +0800, jianchao.wang wrote: > Just don't quite understand the strict definition of "generation" you said. > A allocation->free cycle is a generation ? or a idle->in-flight cycle is a > generation? The idle->in-flight cycle could include the requeue case as above. > Can you clarify this? So, a request is * IN_FLIGHT, if it can be completed by the lower level driver * COMPLETE, if the lower level driver indicated completion but block layer is still processing. * IDLE, if neither of the above two. and generation is bumped up on IDLE -> IN_FLIGHT to distinguish different IN_FLIGHT instances. Thanks. -- tejun