From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] vhost-net: utilize PUBLISH_USED_IDX feature Date: Mon, 17 May 2010 21:08:32 -0700 (PDT) Message-ID: <20100517.210832.27816606.davem@davemloft.net> References: <20100518011931.GA21918@redhat.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: quintela@redhat.com, rusty@rustcorp.com.au, paulmck@linux.vnet.ibm.com, arnd@arndb.de, kvm@vger.kernel.org, virtualization@lists.osdl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, alex.williamson@redhat.com, amit.shah@redhat.com To: mst@redhat.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:46971 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751092Ab0EREIY (ORCPT ); Tue, 18 May 2010 00:08:24 -0400 In-Reply-To: <20100518011931.GA21918@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: From: "Michael S. Tsirkin" Date: Tue, 18 May 2010 04:19:31 +0300 > With PUBLISH_USED_IDX, guest tells us which used entries > it has consumed. This can be used to reduce the number > of interrupts: after we write a used entry, if the guest has not yet > consumed the previous entry, or if the guest has already consumed the > new entry, we do not need to interrupt. > This imporves bandwidth by 30% under some workflows. > > Signed-off-by: Michael S. Tsirkin > --- > > Rusty, Dave, this patch depends on the patch > "virtio: put last seen used index into ring itself" > which is currently destined at Rusty's tree. > Rusty, if you are taking that one for 2.6.35, please > take this one as well. > Dave, any objections? None: Acked-by: David S. Miller