From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ankit Jain Subject: Re: [LSF/MM TOPIC][ATTEND] Improving async io, specifically io_submit latencies Date: Tue, 05 Mar 2013 01:25:16 +0530 Message-ID: <5134FC24.3080009@suse.de> References: <512FB91B.80102@suse.de> <20130228210318.GA3762@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: lsf-pc@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, Jan Kara , Zach Brown , tytso@mit.edu To: Kent Overstreet Return-path: Received: from cantor2.suse.de ([195.135.220.15]:34566 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758295Ab3CDT41 (ORCPT ); Mon, 4 Mar 2013 14:56:27 -0500 In-Reply-To: <20130228210318.GA3762@google.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 03/01/2013 02:33 AM, Kent Overstreet wrote: > On Fri, Mar 01, 2013 at 01:37:55AM +0530, Ankit Jain wrote: >> Hi, >> >> I'm interested in discussing how to improve async io api in the kernel, >> specifically io_submit latencies. >> >> I am working on trying to make io_submit non-blocking. I had posted a >> patch[1] for this earlier on fsdevel and there was some discussion on >> it. I have made some of the improvements suggested there. >> >> The approach attempted in that patch essentially tries to service the >> requests on a separate kernel thread. It was pointed out that this would >> need to ensure that there aren't any unknown task_struct references or >> dependencies under f_op->aio* which might get confused because of the >> kernel thread. Would this kinda full audit be enough or would be it >> considered too fragile? > > Was just talking about this. Completely agreed that we need to do > something about it, but personally I don't think punting everything to > workqueue is a realistic solution. Sure. Like you and others mentioned on this thread, there are possible ways to solve this. I think it would be useful to discuss those and figure out an approach to try for this, at the conference. Thanks, -- Ankit Jain SUSE Labs