Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759455Ab3GaJvl (ORCPT ); Wed, 31 Jul 2013 05:51:41 -0400 Received: from relay.parallels.com ([195.214.232.42]:38665 "EHLO relay.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759415Ab3GaJvi (ORCPT ); Wed, 31 Jul 2013 05:51:38 -0400 Message-ID: <51F8DE28.4000508@parallels.com> Date: Wed, 31 Jul 2013 13:51:36 +0400 From: Maxim Patlasov User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130620 Thunderbird/17.0.7 MIME-Version: 1.0 To: Andrew Morton CC: Dave Kleikamp , , , Zach Brown Subject: Re: [PATCH V8 00/33] loop: Issue O_DIRECT aio using bio_vec References: <1374774659-13121-1-git-send-email-dave.kleikamp@oracle.com> <20130730142820.313f1af6827276df31913106@linux-foundation.org> In-Reply-To: <20130730142820.313f1af6827276df31913106@linux-foundation.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.30.17.2] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1271 Lines: 29 07/31/2013 01:28 AM, Andrew Morton пишет: > On Thu, 25 Jul 2013 12:50:26 -0500 Dave Kleikamp wrote: > >> This patch series adds a kernel interface to fs/aio.c so that kernel code can >> issue concurrent asynchronous IO to file systems. It adds an aio command and >> file system methods which specify io memory with pages instead of userspace >> addresses. >> >> This series was written to reduce the current overhead loop imposes by >> performing synchronus buffered file system IO from a kernel thread. These >> patches turn loop into a light weight layer that translates bios into iocbs. > Do you have any performance numbers? > > Does anyone care much about loop performance? What's the value here? > > OpenVZ uses loopback-device to keep per-container filesystems. We care much about overhead introduced by loop: IO-bound applications run on top of per-container filesystem shouldn't perform worse than on top of host filesystem. So the value for us is zero overhead. Thanks, Maxim -- 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/