Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752182AbcCVTBA (ORCPT ); Tue, 22 Mar 2016 15:01:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36288 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751716AbcCVTAx (ORCPT ); Tue, 22 Mar 2016 15:00:53 -0400 From: Bandan Das To: "Michael Rapoport" Cc: jiangshanlai@gmail.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, mst@redhat.com, tj@kernel.org Subject: Re: vhost threading model References: <1458339291-4093-1-git-send-email-bsd@redhat.com> <201603210758.u2L7wiXA028101@d06av09.portsmouth.uk.ibm.com> <201603220712.u2M7CCfq004548@d06av03.portsmouth.uk.ibm.com> Date: Tue, 22 Mar 2016 15:00:50 -0400 In-Reply-To: <201603220712.u2M7CCfq004548@d06av03.portsmouth.uk.ibm.com> (Michael Rapoport's message of "Tue, 22 Mar 2016 09:12:08 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1274 Lines: 34 "Michael Rapoport" writes: ... > > Well, Elvis is a _theoretical_ example that showed that I/O scheduling in > the vhost improves performance. > I'm not saying we should take Evlis and try to squeeze it into the vhost, > I just want to say that we cannot switch vhost to use workqueues if it > causes performance degradation. > > My opinion is that we need to give it some more thought, much more > performance evaluation, so that we can find the best model. Exactly, I think we are outright discarding using workqueues even without investigating it in detail even though it would be a cleaner implementation using a common framework and thereby more chances of an acceptable solution for upstream. Anyway, if we don't want to go the workqueues way for vhost, cgroups support for workqueues is still something worth having on its own. >> > opportunity for optimization, at least for some workloads... >> > That said, I believe that switching vhost to use workqueues is not > that >> > good idea after all. >> > > > -- > Sincerely yours, > Mike. > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html