Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934817Ab3DISI0 (ORCPT ); Tue, 9 Apr 2013 14:08:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36796 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933610Ab3DISIY (ORCPT ); Tue, 9 Apr 2013 14:08:24 -0400 Date: Tue, 9 Apr 2013 14:08:06 -0400 (EDT) From: Mikulas Patocka X-X-Sender: mpatocka@file.rdu.redhat.com To: Tejun Heo 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 Subject: Re: dm-crypt parallelization patches In-Reply-To: <20130409175753.GA6186@mtj.dyndns.org> Message-ID: 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> <20130409175753.GA6186@mtj.dyndns.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1398 Lines: 42 On Tue, 9 Apr 2013, Tejun Heo wrote: > 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? What do you mean? I used to have a patch that keeps order of requests as they were introduced, but sorting the requests according to sector number is a bit simpler. > > 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. bio_associate_current() is only valid on a system with cgroups and there are no cgroups on the kernel where I tested it. It is an empty function: static inline int bio_associate_current(struct bio *bio) { return -ENOENT; } Mikulas > Thanks. > > -- > tejun > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/