From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754943AbbLDCYI (ORCPT ); Thu, 3 Dec 2015 21:24:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46607 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754740AbbLDCYG (ORCPT ); Thu, 3 Dec 2015 21:24:06 -0500 Subject: Re: [PATCH net-next 3/3] vhost_net: basic polling support To: "Michael S. Tsirkin" References: <1448435489-5949-1-git-send-email-jasowang@redhat.com> <1448435489-5949-4-git-send-email-jasowang@redhat.com> <20151130124233-mutt-send-email-mst@redhat.com> <565D2D7D.4010903@redhat.com> <20151201163939-mutt-send-email-mst@redhat.com> <565E7BC3.2060107@redhat.com> <20151202143522-mutt-send-email-mst@redhat.com> Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org From: Jason Wang Message-ID: <5660F940.3000202@redhat.com> Date: Fri, 4 Dec 2015 10:24:00 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <20151202143522-mutt-send-email-mst@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/02/2015 08:36 PM, Michael S. Tsirkin wrote: > On Wed, Dec 02, 2015 at 01:04:03PM +0800, Jason Wang wrote: >> >> On 12/01/2015 10:43 PM, Michael S. Tsirkin wrote: >>> On Tue, Dec 01, 2015 at 01:17:49PM +0800, Jason Wang wrote: >>>> On 11/30/2015 06:44 PM, Michael S. Tsirkin wrote: >>>>> On Wed, Nov 25, 2015 at 03:11:29PM +0800, Jason Wang wrote: >>>>>>> This patch tries to poll for new added tx buffer or socket receive >>>>>>> queue for a while at the end of tx/rx processing. The maximum time >>>>>>> spent on polling were specified through a new kind of vring ioctl. >>>>>>> >>>>>>> Signed-off-by: Jason Wang >>>>> One further enhancement would be to actually poll >>>>> the underlying device. This should be reasonably >>>>> straight-forward with macvtap (especially in the >>>>> passthrough mode). >>>>> >>>>> >>>> Yes, it is. I have some patches to do this by replacing >>>> skb_queue_empty() with sk_busy_loop() but for tap. >>> We probably don't want to do this unconditionally, though. >>> >>>> Tests does not show >>>> any improvement but some regression. >>> Did you add code to call sk_mark_napi_id on tap then? >>> sk_busy_loop won't do anything useful without. >> Yes I did. Probably something wrong elsewhere. > Is this for guest-to-guest? Nope. Like you said below, since it requires NAPI so it was external host to guest. > the patch to do napi > for tap is still not upstream due to minor performance > regression. Want me to repost it? Sure, I've played this a little bit in the past too. > >>>> Maybe it's better to test macvtap. >>> Same thing ... >>> > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html