From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=59693 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1P2Zi5-0001Hr-Bx for qemu-devel@nongnu.org; Sun, 03 Oct 2010 21:19:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1P2Zi4-0005v5-CT for qemu-devel@nongnu.org; Sun, 03 Oct 2010 21:19:21 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:39377) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1P2Zi4-0005uy-0f for qemu-devel@nongnu.org; Sun, 03 Oct 2010 21:19:20 -0400 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e34.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id o9419jkM032503 for ; Sun, 3 Oct 2010 19:09:45 -0600 Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o941JG78116132 for ; Sun, 3 Oct 2010 19:19:16 -0600 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id o941JFCG010444 for ; Sun, 3 Oct 2010 19:19:16 -0600 Message-ID: <4CA92B79.2030805@linux.vnet.ibm.com> Date: Sun, 03 Oct 2010 20:18:49 -0500 From: Anthony Liguori MIME-Version: 1.0 References: <1285855312-11739-1-git-send-email-stefanha@linux.vnet.ibm.com> <4CA862A7.2080302@redhat.com> <20101003135138.GA19775@redhat.com> <4CA89185.6070302@redhat.com> <20101003142828.GB19775@redhat.com> In-Reply-To: <20101003142828.GB19775@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [PATCH] virtio: Use ioeventfd for virtqueue notify List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Steve Dobbelstein , Anthony Liguori , Stefan Hajnoczi , kvm@vger.kernel.org, qemu-devel@nongnu.org, Khoa Huynh , Avi Kivity , sri@linux.vnet.ibm.com On 10/03/2010 09:28 AM, Michael S. Tsirkin wrote: > >> This is using eventfd as well. >> > Sorry, I meant irqfd. > I've tried using irqfd in userspace. It hurts performance quite a bit compared to doing an ioctl so I would suspect this too. A last_used_idx or similar mechanism should help performance quite a bit on top of ioeventfd too. Regards, Anthony Liguori >> -- >> error compiling committee.c: too many arguments to function >>