From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [RFC][PATCH 0/10] I/O context inheritance Date: Tue, 22 Apr 2008 16:54:18 +0200 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 Return-path: Content-Disposition: inline In-Reply-To: <20080422.230318.112756414.taka@valinux.co.jp> Sender: linux-kernel-owner@vger.kernel.org To: Hirokazu Takahashi Cc: agk@sourceware.org, dm-devel@redhat.com, linux-kernel@vger.kernel.org List-Id: dm-devel.ids 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