From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754412Ab3AQXtl (ORCPT ); Thu, 17 Jan 2013 18:49:41 -0500 Received: from mx2.parallels.com ([64.131.90.16]:53388 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752076Ab3AQXtk convert rfc822-to-8bit (ORCPT ); Thu, 17 Jan 2013 18:49:40 -0500 From: James Bottomley To: "sedat.dilek@gmail.com" CC: Dave Kleikamp , "linux-fsdevel@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Zach Brown , Maxim Patlasov Subject: Re: [PATCH V5 00/30] loop: Issue O_DIRECT aio using bio_vec Thread-Topic: [PATCH V5 00/30] loop: Issue O_DIRECT aio using bio_vec Thread-Index: AQHN9AckBU/BbJkf9Eempikh7KsAy5hMy86AgAHs3AA= Date: Thu, 17 Jan 2013 23:49:37 +0000 Message-ID: <1358466576.2394.44.camel@dabdike.int.hansenpartnership.com> References: <1357761525-22718-1-git-send-email-dave.kleikamp@oracle.com> <1358353978.2384.50.camel@dabdike.int.hansenpartnership.com> In-Reply-To: Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [46.65.52.191] Content-Type: text/plain; charset=US-ASCII Content-ID: Content-Transfer-Encoding: 7BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2013-01-16 at 19:25 +0100, Sedat Dilek wrote: > On Wed, Jan 16, 2013 at 5:32 PM, James Bottomley > wrote: > > On Wed, 2013-01-09 at 13:58 -0600, Dave Kleikamp wrote: > >> This patchset was begun by Zach Brown and was originally submitted for > >> review in October, 2009. Feedback was positive, and I have picked up > >> where he left off, porting his patches to the latest mainline kernel > >> and adding support more file systems. > >> > >> 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. > >> > >> It introduces new file ops, read_iter() and write_iter(), that replace the > >> aio_read() and aio_write() operations. The iov_iter structure can now contain > >> either a user-space iovec or a kernel-space bio_vec. Since it would be > >> overly complicated to replace every instance of aio_read() and aio_write(), > >> the old operations are not removed, but file systems implementing the new > >> ones need not keep the old ones. > >> > >> Changes from V4 include: > >> * moved iov-iter.c from mm/ to fs/ > >> * removed dio_aligned helper > >> * insured that FUA write to loop device is committed to media > >> * removed no-longer-used REQ_KERNEL define > >> > >> These patches apply to 3.8-rc2 and are also available at: > >> git://github.com/kleikamp/linux-shaggy.git loop_2013_01_04 > >> > >> My hopes are that this patchset is finally ready for linux-next. > > > > Just a note that we at parallels are anxiously awaiting this too. Our > > rewrite of the linux loop device to be more efficient (and not double > > cache) depends on this work. I should also note that we've been testing > > these patches (albeit backported to a RHEL kernel as a current work > > base) with no problems reported so far. > > > > Hi James, > > do you have a location for me for testing this patchset from parallels? You mean the RHEL kernels? Not really; they're just proof of concept and not released yet. Our mainline effort won't really begin until we know the fate of the DIO patches. James