From patchwork Wed Mar 31 07:11:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xuan Zhuo X-Patchwork-Id: 12174493 X-Patchwork-Delegate: kuba@kernel.org 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=unavailable 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 A7B37C433C1 for ; Wed, 31 Mar 2021 07:12:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 81487619E2 for ; Wed, 31 Mar 2021 07:12:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233962AbhCaHMS (ORCPT ); Wed, 31 Mar 2021 03:12:18 -0400 Received: from out30-42.freemail.mail.aliyun.com ([115.124.30.42]:57785 "EHLO out30-42.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233912AbhCaHLp (ORCPT ); Wed, 31 Mar 2021 03:11:45 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R101e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04423;MF=xuanzhuo@linux.alibaba.com;NM=1;PH=DS;RN=20;SR=0;TI=SMTPD_---0UTvslU-_1617174702; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0UTvslU-_1617174702) by smtp.aliyun-inc.com(127.0.0.1); Wed, 31 Mar 2021 15:11:42 +0800 From: Xuan Zhuo To: netdev@vger.kernel.org Cc: "Michael S. Tsirkin" , Jason Wang , "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 Subject: [PATCH net-next v3 6/8] virtio-net: xsk zero copy xmit kick by threshold Date: Wed, 31 Mar 2021 15:11:37 +0800 Message-Id: <20210331071139.15473-7-xuanzhuo@linux.alibaba.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210331071139.15473-1-xuanzhuo@linux.alibaba.com> References: <20210331071139.15473-1-xuanzhuo@linux.alibaba.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org 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. 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); }