From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: Re: [PATCH v2 2/2] virtio-ring: Allocate indirect buffers from cache when possible Date: Wed, 29 Aug 2012 22:46:19 +0200 Message-ID: <503E7F9B.8010402@gmail.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> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120829181235.GE7877@redhat.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: "Michael S. Tsirkin" Cc: avi@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.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