Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752830AbaLBKAk (ORCPT ); Tue, 2 Dec 2014 05:00:40 -0500 Received: from mx0.aculab.com ([213.249.233.131]:49897 "HELO mx0.aculab.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751310AbaLBKAi (ORCPT ); Tue, 2 Dec 2014 05:00:38 -0500 From: David Laight To: "'Jason Wang'" , "Michael S. Tsirkin" CC: "virtualization@lists.linux-foundation.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "davem@davemloft.net" , "pagupta@redhat.com" Subject: RE: [PATCH RFC v4 net-next 0/5] virtio_net: enabling tx interrupts Thread-Topic: [PATCH RFC v4 net-next 0/5] virtio_net: enabling tx interrupts Thread-Index: AQHQDd5DHvRvdWthCEWkhNyyod07HJx8ETyg Date: Tue, 2 Dec 2014 10:00:06 +0000 Message-ID: <063D6719AE5E284EB5DD2968C1650D6D1CA007CC@AcuExch.aculab.com> References: <1417429028-11971-1-git-send-email-jasowang@redhat.com> <20141201104223.GB16108@redhat.com> <1417490120.4405.2@smtp.corp.redhat.com> In-Reply-To: <1417490120.4405.2@smtp.corp.redhat.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.202.99.200] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id sB2A0ldY015760 From: Jason Wang > > On Mon, Dec 01, 2014 at 06:17:03PM +0800, Jason Wang wrote: > >> Hello: > >> > >> We used to orphan packets before transmission for virtio-net. This > >> breaks > >> socket accounting and can lead serveral functions won't work, e.g: > >> > >> - Byte Queue Limit depends on tx completion nofication to work. > >> - Packet Generator depends on tx completion nofication for the last > >> transmitted packet to complete. > >> - TCP Small Queue depends on proper accounting of sk_wmem_alloc to > >> work. > >> > >> This series tries to solve the issue by enabling tx interrupts. To > >> minize > >> the performance impacts of this, several optimizations were used: > >> > >> - In guest side, virtqueue_enable_cb_delayed() was used to delay the tx > >> interrupt untile 3/4 pending packets were sent. Doesn't that give problems for intermittent transmits? ... David ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?