From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753372Ab2H2UqF (ORCPT ); Wed, 29 Aug 2012 16:46:05 -0400 Received: from mail-ey0-f174.google.com ([209.85.215.174]:44062 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751894Ab2H2UqE (ORCPT ); Wed, 29 Aug 2012 16:46:04 -0400 Message-ID: <503E7F9B.8010402@gmail.com> Date: Wed, 29 Aug 2012 22:46:19 +0200 From: Sasha Levin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120826 Thunderbird/14.0 MIME-Version: 1.0 To: "Michael S. Tsirkin" CC: rusty@rustcorp.com.au, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, avi@redhat.com, kvm@vger.kernel.org Subject: Re: [PATCH v2 2/2] virtio-ring: Allocate indirect buffers from cache when possible References: <1346159043-16446-1-git-send-email-levinsasha928@gmail.com> <1346159043-16446-2-git-send-email-levinsasha928@gmail.com> <20120829153812.GD7407@redhat.com> <503E4DD9.1020102@gmail.com> <20120829181235.GE7877@redhat.com> In-Reply-To: <20120829181235.GE7877@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/29/2012 08:12 PM, Michael S. Tsirkin wrote: >>> > > What is a good default for net? I guess max sg? >> > >> > I think that it depends on the workload. I'd say we should keep the default to 0 >> > (disabled) unless we can have a good way to adjust it to the load. > For *all* drivers? > > Then it is mostly useless. No one has the time to tweak module > parameters in real life. > > For virtio-net, 16+1 is not too much and ensures we always > use the cache. > > If that works better than 0 I would say run with 17. I was being extra-cautious with leaving it disabled until specifically enabled because I assumed that this would be one of the first comments I'll get if it was enabled by default :) If you're comfortable with setting it to a sane default like 17, I'm perfectly fine with that as well. Thanks, Sasha