Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752283Ab3HUQaf (ORCPT ); Wed, 21 Aug 2013 12:30:35 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:25967 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752207Ab3HUQab (ORCPT ); Wed, 21 Aug 2013 12:30:31 -0400 Message-ID: <5214EB1E.5050407@oracle.com> Date: Wed, 21 Aug 2013 11:30:22 -0500 From: Dave Kleikamp User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130806 Thunderbird/17.0.8 MIME-Version: 1.0 To: Benjamin LaHaise CC: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , "Maxim V. Patlasov" , Zach Brown , linux-aio@kvack.org 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> <20130821130231.GG13330@kvack.org> In-Reply-To: <20130821130231.GG13330@kvack.org> X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2013 Lines: 43 Ben, First, let me apologize for neglecting to copy you and linux-aio on the applicable patches. I've been carrying along this patchset, assuming I had gotten the proper cc's correct a while back, but I somehow missed the aio pieces. On 08/21/2013 08:02 AM, Benjamin LaHaise wrote: > Hello Dave, > > On Thu, Jul 25, 2013 at 12:50:26PM -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. > > First off, have you tested that this series actually works when merged with > the pending AIO changes from Kent? There a git tree with those pending > changes at git://git.kvack.org/~bcrl/aio-next.git , and they're in > linux-next. I've lightly tested the patchset against the linux-next tree, running a fio job on loop-mounted filesystems of different fs types. > One of the major problems your changeset continues to carry is that your > new read_iter/write_iter operations permit blocking (implicitely), which > really isn't what we want for aio. If you're going to introduce a new api, > it should be made non-blocking, and enforce that non-blocking requirement > (ie warn when read_iter/write_iter methods perform blockin operations, > similar to the warnings when scheduling in atomic mode). This means more > changes for some filesystem code involved, something that people have been > avoiding for years, but which really needs to be done. I'm not really sure how the read_iter and write_iter operations are more likely to block than the current aio_read and aio_write operations. Am I missing something? Thanks, Dave -- 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/