From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [Qemu-devel] Re: [PATCH 2/3] virtio-pci: Use ioeventfd for virtqueue notify Date: Sun, 14 Nov 2010 14:19:10 +0200 Message-ID: <4CDFD3BE.8090702@redhat.com> References: <1289483242-6069-1-git-send-email-stefanha@linux.vnet.ibm.com> <1289483242-6069-3-git-send-email-stefanha@linux.vnet.ibm.com> <20101111164518.GA28773@infradead.org> <4CDFBB19.7010702@redhat.com> <4CDFC288.9050800@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Christoph Hellwig , Stefan Hajnoczi , qemu-devel@nongnu.org, kvm@vger.kernel.org, "Michael S. Tsirkin" To: Stefan Hajnoczi Return-path: Received: from mx1.redhat.com ([209.132.183.28]:32690 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755332Ab0KNMTi (ORCPT ); Sun, 14 Nov 2010 07:19:38 -0500 In-Reply-To: <4CDFC288.9050800@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 11/14/2010 01:05 PM, Avi Kivity wrote: >> I agree, but let's enable virtio-ioeventfd carefully because bad code >> is out there. > > > Sure. Note as long as the thread waiting on ioeventfd doesn't consume > too much cpu, it will awaken quickly and we won't have the > "transaction per timeslice" effect. > > btw, what about virtio-blk with linux-aio? Have you benchmarked that > with and without ioeventfd? > And, what about efficiency? As in bits/cycle? -- error compiling committee.c: too many arguments to function