From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH v2 2/2] virtio-ring: Allocate indirect buffers from cache when possible Date: Thu, 30 Aug 2012 01:52:49 +0300 Message-ID: <20120829225249.GB9146@redhat.com> 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> <503E7F9B.8010402@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <503E7F9B.8010402@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Sasha Levin Cc: virtualization@lists.linux-foundation.org, avi@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: virtualization@lists.linuxfoundation.org On Wed, Aug 29, 2012 at 10:46:19PM +0200, Sasha Levin wrote: > 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 If our testing shows it helps and does not trigger regressions, then why not? module params are mostly there for developers. They are not all that helpful to users. > _______________________________________________ > Virtualization mailing list > Virtualization@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/virtualization