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=-14.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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=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 0F997C433E6 for ; Thu, 28 Jan 2021 15:18:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B94DE64DED for ; Thu, 28 Jan 2021 15:18:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231210AbhA1PS3 (ORCPT ); Thu, 28 Jan 2021 10:18:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53436 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231390AbhA1PSO (ORCPT ); Thu, 28 Jan 2021 10:18:14 -0500 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F55BC0613D6; Thu, 28 Jan 2021 07:17:34 -0800 (PST) Received: by mail-pj1-x102c.google.com with SMTP id a20so4031276pjs.1; Thu, 28 Jan 2021 07:17:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=2Nye8p/WF2NWdxjWCcs2X/vHGUhlnVaM/5kQ/1QbWn4=; b=bCsqzeuAGuApSZxxJAxr75qJ6gUgKRhrPGQz7yXrp/xRnXsoWxybscn4vh5QrsNaCz WGvjTsbc0j/TCCqYassW1O3Aj4UA9+6wUte1CheKYLbln16eYunXmiS6njtyf53J4z8x fy2Bs1YR/wQNpMc6SRoarSzGbsxL/o4EyiDDfDpCOPtibpm1yyQiay56ZI0+6Z534X9F tER6yltuLGG/ThN9I/waSYyu+DAkZzvdPtTINvjH8pzC8Xzh2J4hVT3phFO2gIXZ74gk Nmfq4df1X31bmJVBshpd66Y31NOpDpHa5GylyKb3a+fDroT9tkcmoE2PZ9Yb40Xa24St 2oaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=2Nye8p/WF2NWdxjWCcs2X/vHGUhlnVaM/5kQ/1QbWn4=; b=JhlQwU9jHcsI7s0phu/+hM/xmM5MoIH/mrA4q5RqSgh88imLRMtaxEQd0900ApM579 nA6LzoB1nl/Wsw24zOeqHWxXV61TXPKQuxwH8ojmc6+ik+XllMsgjyrxUGgP7ZIG83gn AxRjqna1nYNLmU5UsGHHuICrSjWO7Y/wKrCU/zVUyVH4QN4bzg0nYi6vsITqJ0HNW+Du VxZawFBpq2poDnKUILGo5PXz9vGFnTwjRGS5+vfBZ3DWmwv25mjC1q2zeb0C4aYRTNg9 MJIzskUv+5DHWy+VvZyPv8bPhlnU/rN3lIMKIeXnbm7bHwWJgEzJew4GONjVR6b7Q6rz 2cXg== X-Gm-Message-State: AOAM532+qMRbtz34zUw7XWsdLRzEkrzKrxbMvGfTvHSbeMr1O/zS+s5Z GMHMKoKMKTCrcjF32L/UStw= X-Google-Smtp-Source: ABdhPJwsZmg60NuhdyVTl0ndOhEzxWR2wvZ9Xe6KyHOOKqOBHUgMZIrAS9dWYtala5iaIw2DUWdPgg== X-Received: by 2002:a17:902:b213:b029:db:3a3e:d8ad with SMTP id t19-20020a170902b213b02900db3a3ed8admr47121plr.73.1611847053795; Thu, 28 Jan 2021 07:17:33 -0800 (PST) Received: from [192.168.1.18] (i121-115-229-245.s42.a013.ap.plala.or.jp. [121.115.229.245]) by smtp.googlemail.com with ESMTPSA id ne6sm5330632pjb.44.2021.01.28.07.17.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 28 Jan 2021 07:17:33 -0800 (PST) Subject: Re: [PATCH bpf-next 1/3] net: veth: introduce bulking for XDP_PASS To: Lorenzo Bianconi , bpf@vger.kernel.org Cc: netdev@vger.kernel.org, davem@davemloft.net, kuba@kernel.org, ast@kernel.org, daniel@iogearbox.net, lorenzo.bianconi@redhat.com, brouer@redhat.com, toke@redhat.com References: From: Toshiaki Makita Message-ID: Date: Fri, 29 Jan 2021 00:17:27 +0900 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2021/01/27 3:41, Lorenzo Bianconi wrote: > Introduce bulking support for XDP_PASS verdict forwarding skbs to > the networking stack > > Signed-off-by: Lorenzo Bianconi > --- > drivers/net/veth.c | 43 ++++++++++++++++++++++++++----------------- > 1 file changed, 26 insertions(+), 17 deletions(-) > > diff --git a/drivers/net/veth.c b/drivers/net/veth.c > index 6e03b619c93c..23137d9966da 100644 > --- a/drivers/net/veth.c > +++ b/drivers/net/veth.c > @@ -35,6 +35,7 @@ > #define VETH_XDP_HEADROOM (XDP_PACKET_HEADROOM + NET_IP_ALIGN) > > #define VETH_XDP_TX_BULK_SIZE 16 > +#define VETH_XDP_BATCH 8 > > struct veth_stats { > u64 rx_drops; > @@ -787,27 +788,35 @@ static int veth_xdp_rcv(struct veth_rq *rq, int budget, > int i, done = 0; > > for (i = 0; i < budget; i++) { > - void *ptr = __ptr_ring_consume(&rq->xdp_ring); > - struct sk_buff *skb; > + void *frames[VETH_XDP_BATCH]; > + void *skbs[VETH_XDP_BATCH]; > + int i, n_frame, n_skb = 0; 'i' is a shadowed variable. I think this may be confusing. > > - if (!ptr) > + n_frame = __ptr_ring_consume_batched(&rq->xdp_ring, frames, > + VETH_XDP_BATCH); This apparently exceeds the budget. This will process budget*VETH_XDP_BATCH packets at most. (You are probably aware of this because you return 'i' instead of 'done'?) Also I'm not sure if we need to introduce __ptr_ring_consume_batched() here. The function just does __ptr_ring_consume() n times. IIUC Your final code looks like this: for (budget) { n_frame = __ptr_ring_consume_batched(VETH_XDP_BATCH); for (n_frame) { if (frame is XDP) xdpf[n_xdpf++] = to_xdp(frame); else skbs[n_skb++] = frame; } if (n_xdpf) veth_xdp_rcv_batch(xdpf); for (n_skb) { skb = veth_xdp_rcv_skb(skbs[i]); napi_gro_receive(skb); } } Your code processes VETH_XDP_BATCH packets at a time no matter whether each of them is xdp_frame or skb, but I think you actually want to process VETH_XDP_BATCH xdp_frames at a time? Then, why not doing like this? for (budget) { ptr = __ptr_ring_consume(); if (ptr is XDP) { if (n_xdpf >= VETH_XDP_BATCH) { veth_xdp_rcv_batch(xdpf); n_xdpf = 0; } xdpf[n_xdpf++] = to_xdp(ptr); } else { skb = veth_xdp_rcv_skb(ptr); napi_gro_receive(skb); } } if (n_xdpf) veth_xdp_rcv_batch(xdpf); Toshiaki Makita