From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753540Ab0GZQG7 (ORCPT ); Mon, 26 Jul 2010 12:06:59 -0400 Received: from hera.kernel.org ([140.211.167.34]:38029 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750933Ab0GZQG5 (ORCPT ); Mon, 26 Jul 2010 12:06:57 -0400 Message-ID: <4C4DB247.9060709@kernel.org> Date: Mon, 26 Jul 2010 18:05:27 +0200 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.2.4) Gecko/20100608 Thunderbird/3.1 MIME-Version: 1.0 To: "Michael S. Tsirkin" CC: Oleg Nesterov , Sridhar Samudrala , netdev , lkml , "kvm@vger.kernel.org" , Andrew Morton , Dmitri Vorobiev , Jiri Kosina , Thomas Gleixner , Ingo Molnar , Andi Kleen Subject: Re: [PATCH UPDATED 1/3] vhost: replace vhost_workqueue with per-vhost kthread References: <4C03D983.9010905@kernel.org> <20100531160020.GC3067@redhat.com> <4C04D41B.4050704@kernel.org> <4C06A580.9060300@kernel.org> <20100722155840.GA1743@redhat.com> <4C48B664.9000109@kernel.org> <20100724191447.GA4972@redhat.com> <4C4BEAA2.6040301@kernel.org> <20100726152510.GA26223@redhat.com> <4C4DAB14.5050809@kernel.org> <20100726155014.GA26412@redhat.com> In-Reply-To: <20100726155014.GA26412@redhat.com> X-Enigmail-Version: 1.1.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Mon, 26 Jul 2010 16:05:29 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On 07/26/2010 05:50 PM, Michael S. Tsirkin wrote: >> Hmmm... I'm not quite sure whether it's an optimization. I thought >> the patch was due to feeling uncomfortable about using barriers? > > Oh yes. But getting rid of barriers is what motivated me originally. Yeah, getting rid of barriers is always good. :-) > Is there a git tree with kthread_worker applied? > I might do this just for fun ... git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git for-next For the original implementaiton, please take a look at commit b56c0d8937e665a27d90517ee7a746d0aa05af46. * Can you please keep the outer goto repeat loop? I just don't like outermost for (;;). * Placing try_to_freeze() could be a bit annoying. It shouldn't be executed when there's a work to flush. * I think A - B <= 0 test would be more familiar. At least time_before/after() are implemented that way. Thanks. -- tejun