From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: dm-crypt parallelization patches Date: Tue, 9 Apr 2013 10:57:53 -0700 Message-ID: <20130409175753.GA6186@mtj.dyndns.org> References: <20130326122713.GC27610@agk-dp.fab.redhat.com> <5151FF82.6090405@gmail.com> <20130326202837.GA5599@redhat.com> <20130328185327.GF14088@htj.dyndns.org> <20130328193343.GA15969@redhat.com> <20130328194443.GG14088@htj.dyndns.org> <20130328203808.GC15969@redhat.com> <20130328204522.GA25501@mtj.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Mikulas Patocka Cc: Jens Axboe , Vivek Goyal , Mike Snitzer , Milan Broz , dm-devel@redhat.com, Andi Kleen , dm-crypt@saout.de, linux-kernel@vger.kernel.org, Christoph Hellwig , Christian Schmidt List-Id: dm-devel.ids On Tue, Apr 09, 2013 at 01:51:43PM -0400, Mikulas Patocka wrote: > The patch dm-crypt-sort-requests.patch sorts write requests submitted by a > single thread. The requests are sorted according to the sector number, > rb-tree is used for efficient sorting. Hmmm? Why not just keep the issuing order along with plugging boundaries? > So it seems that CFQ has some deficiency that it cannot merge adjacent > requests done by different processes. As I wrote before, please use bio_associate_current(). Currently, dm-crypt is completely messing up all the context information that cfq depends on to schedule IOs. Of course, it doesn't perform well. Thanks. -- tejun