From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA0ADC433ED for ; Tue, 6 Apr 2021 06:59:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 93DCD60FE7 for ; Tue, 6 Apr 2021 06:59:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244103AbhDFG7b (ORCPT ); Tue, 6 Apr 2021 02:59:31 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:60977 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244099AbhDFG7b (ORCPT ); Tue, 6 Apr 2021 02:59:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617692363; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=MEh2o752ANYQ9L9YTCxFAQMwQEPClrn186DoZd/3tu4=; b=EK7EsUOVs+CN/FvgM59IiWJiUqM4C3cUjkxYtYHLq8BO1I2P/LmmRqvbwA0L9hrNB/FLT7 vdA+tzNaPHE3Pop3rpQPqT4EXgwPPjfiqIFV25UjtnAi16ah9+/LNo/EFHfd87L7ytb3p5 sscKrwTXV/gy0sJWzGnKHewaxb0WNkg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-363-_QPCqdfDPSWjsL08fqIxGA-1; Tue, 06 Apr 2021 02:59:19 -0400 X-MC-Unique: _QPCqdfDPSWjsL08fqIxGA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DE1901018F70; Tue, 6 Apr 2021 06:59:16 +0000 (UTC) Received: from wangxiaodeMacBook-Air.local (ovpn-13-95.pek2.redhat.com [10.72.13.95]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9BAA019D9F; Tue, 6 Apr 2021 06:59:01 +0000 (UTC) Subject: Re: [PATCH net-next v3 6/8] virtio-net: xsk zero copy xmit kick by threshold To: Xuan Zhuo , netdev@vger.kernel.org Cc: "Michael S. Tsirkin" , "David S. Miller" , Jakub Kicinski , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , Magnus Karlsson , Jonathan Lemon , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , KP Singh , virtualization@lists.linux-foundation.org, bpf@vger.kernel.org, Dust Li References: <20210331071139.15473-1-xuanzhuo@linux.alibaba.com> <20210331071139.15473-7-xuanzhuo@linux.alibaba.com> From: Jason Wang Message-ID: Date: Tue, 6 Apr 2021 14:59:00 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.9.0 MIME-Version: 1.0 In-Reply-To: <20210331071139.15473-7-xuanzhuo@linux.alibaba.com> Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org ÔÚ 2021/3/31 ÏÂÎç3:11, Xuan Zhuo дµÀ: > After testing, the performance of calling kick every time is not stable. > And if all the packets are sent and kicked again, the performance is not > good. So add a module parameter to specify how many packets are sent to > call a kick. > > 8 is a relatively stable value with the best performance. Please add some perf numbers here. Thanks > > Signed-off-by: Xuan Zhuo > Reviewed-by: Dust Li > --- > drivers/net/virtio_net.c | 23 ++++++++++++++++++++--- > 1 file changed, 20 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 259fafcf6028..d7e95f55478d 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -29,10 +29,12 @@ module_param(napi_weight, int, 0444); > > static bool csum = true, gso = true, napi_tx = true; > static int xsk_budget = 32; > +static int xsk_kick_thr = 8; > module_param(csum, bool, 0444); > module_param(gso, bool, 0444); > module_param(napi_tx, bool, 0644); > module_param(xsk_budget, int, 0644); > +module_param(xsk_kick_thr, int, 0644); > > /* FIXME: MTU in config. */ > #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN) > @@ -2612,6 +2614,8 @@ static int virtnet_xsk_xmit_batch(struct send_queue *sq, > struct xdp_desc desc; > int err, packet = 0; > int ret = -EAGAIN; > + int need_kick = 0; > + int kicks = 0; > > if (sq->xsk.last_desc.addr) { > err = virtnet_xsk_xmit(sq, pool, &sq->xsk.last_desc); > @@ -2619,6 +2623,7 @@ static int virtnet_xsk_xmit_batch(struct send_queue *sq, > return -EBUSY; > > ++packet; > + ++need_kick; > --budget; > sq->xsk.last_desc.addr = 0; > } > @@ -2642,13 +2647,25 @@ static int virtnet_xsk_xmit_batch(struct send_queue *sq, > } > > ++packet; > + ++need_kick; > + if (need_kick > xsk_kick_thr) { > + if (virtqueue_kick_prepare(sq->vq) && > + virtqueue_notify(sq->vq)) > + ++kicks; > + > + need_kick = 0; > + } > } > > if (packet) { > - if (virtqueue_kick_prepare(sq->vq) && > - virtqueue_notify(sq->vq)) { > + if (need_kick) { > + if (virtqueue_kick_prepare(sq->vq) && > + virtqueue_notify(sq->vq)) > + ++kicks; > + } > + if (kicks) { > u64_stats_update_begin(&sq->stats.syncp); > - sq->stats.kicks += 1; > + sq->stats.kicks += kicks; > u64_stats_update_end(&sq->stats.syncp); > } >