Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757629Ab2EVKNh (ORCPT ); Tue, 22 May 2012 06:13:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:20450 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754900Ab2EVKNg (ORCPT ); Tue, 22 May 2012 06:13:36 -0400 Message-ID: <4FBB66C6.2020701@redhat.com> Date: Tue, 22 May 2012 18:13:26 +0800 From: Jason Wang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Shirley Ma CC: "Michael S. Tsirkin" , eric.dumazet@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, ebiederm@xmission.com, davem@davemloft.net Subject: Re: [V2 PATCH 9/9] vhost: zerocopy: poll vq in zerocopy callback References: <20120502033901.11782.13157.stgit@amd-6168-8-1.englab.nay.redhat.com> <20120502034254.11782.27314.stgit@amd-6168-8-1.englab.nay.redhat.com> <1337100630.8220.4.camel@oc3660625478.ibm.com> <4FB317C8.90002@redhat.com> <1337181027.10741.13.camel@oc3660625478.ibm.com> <20120516151444.GC9934@redhat.com> <1337189525.10741.24.camel@oc3660625478.ibm.com> <4FB4677A.8020402@redhat.com> <1337268862.10741.58.camel@oc3660625478.ibm.com> <4FB61D57.4030103@redhat.com> <1337354974.12999.12.camel@oc3660625478.ibm.com> <4FB9DB24.2040408@redhat.com> <1337614972.12999.56.camel@oc3660625478.ibm.com> <1337616766.12999.81.camel@oc3660625478.ibm.com> In-Reply-To: <1337616766.12999.81.camel@oc3660625478.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 907 Lines: 22 On 05/22/2012 12:12 AM, Shirley Ma wrote: > Then it could be too early for vhost to notify guest anywhere in > handle_tx for zerocopy. Then we might need to remove any notification in > handle_tx for zerocopy to vhost zerocopy callback instead. > > Adding vhost_poll_queue in vhost zerocopy callback unconditionally would > consume unnecessary cpu. > > We need to think about a better solution here. A possible idea is only call vhost_poll_queue only when the packet of used_event were sent: if there's no out-of-order completion vhost could signal the guest; if there is, let the pending packets before used_event call vhost_poll_queue. > Thanks > Shirley -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/