From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764701AbYDVOyd (ORCPT ); Tue, 22 Apr 2008 10:54:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756386AbYDVOy0 (ORCPT ); Tue, 22 Apr 2008 10:54:26 -0400 Received: from brick.kernel.dk ([87.55.233.238]:27898 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754786AbYDVOyZ (ORCPT ); Tue, 22 Apr 2008 10:54:25 -0400 Date: Tue, 22 Apr 2008 16:54:18 +0200 From: Jens Axboe To: Hirokazu Takahashi Cc: agk@sourceware.org, dm-devel@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCH 0/10] I/O context inheritance Message-ID: <20080422145418.GL12774@kernel.dk> References: <20080422.224935.00673711.taka@valinux.co.jp> <20080422.230318.112756414.taka@valinux.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080422.230318.112756414.taka@valinux.co.jp> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 22 2008, Hirokazu Takahashi wrote: > Hi, > > Sorry, these patches are for linux-2.6.25. > > > This series of patches make the block I/O layer and the I/O schedulers > > be able to determine the right io_context of every I/O. > > > > The current implementation of the block I/O layer and the I/O schedulers > > assume that the current process is the one which issued the given I/O, > > then use the io_context of this process to control the I/O. > > But this assumption isn't quite right because several kernel threads > > will handle I/O requests on behalf of the processes which originated them. > > This often happens when you want to use device mapper modules. > > > > The patches make every bio has a pointer to an io_context, which will > > be set when it is allocated or cloned. So it makes it possible to find > > the right io_context from any bio at any place. > > > > I'm waiting for your comments. Can you give a brief summary of what you need this stuff for? -- Jens Axboe