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=-12.8 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,SPF_HELO_NONE,SPF_PASS 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 A96EFC4320A for ; Tue, 31 Aug 2021 23:24:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8C12360F91 for ; Tue, 31 Aug 2021 23:24:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240043AbhHaXZC (ORCPT ); Tue, 31 Aug 2021 19:25:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47760 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229917AbhHaXZB (ORCPT ); Tue, 31 Aug 2021 19:25:01 -0400 Received: from mail-il1-x132.google.com (mail-il1-x132.google.com [IPv6:2607:f8b0:4864:20::132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50AAAC061575; Tue, 31 Aug 2021 16:24:05 -0700 (PDT) Received: by mail-il1-x132.google.com with SMTP id r6so1302321ilt.13; Tue, 31 Aug 2021 16:24:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:message-id:in-reply-to:references:subject :mime-version:content-transfer-encoding; bh=6oKV8IdE9hPbDCoLfHJP5NK4UoVBw4HqfdTpOhxuQrE=; b=G0oawfSIjFw0lxTURt14h/Is4hpgl7yRuEBxOVZSxtuuzvE53S2wZMKxhJGmmQqaW/ eaasialaFigj9OOz/3sh70b2boULXGrHxFx1XnEOiVu9e5QeyOQYwd3aw+CIAKnyWv97 oeYD5chsyARfJeCkGrxh7jtmoJo72WgB5wZ6XwZp9tEei9HWpSsFgtA2t5P0U5WVAwg6 9AqTSOSvzsUp/7CFhzPIu5iSeQ+42MlrmDPkjAGckq+IYc8kGK3M7dQdfs+sxmh4ubfx ZbRCzNJPYDOGLmBNWZQhkAd5t+ZCrzWhazChBRwqa/WRqPnyiwPuw/nKKD+ziHk7KkjU oNsg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:content-transfer-encoding; bh=6oKV8IdE9hPbDCoLfHJP5NK4UoVBw4HqfdTpOhxuQrE=; b=Ojqaxp3gNW18Ihfg2b1NXne6N2VLv3RtI/338w4HHEOP1HsKe3qBkKBPzjk/oO837Z 6Hgvii55vwTde/v/GRDioUu/8G/G0XcxeZH/10/P0RciIgDfwpHjwY2eFlypwqKDWEzI BvSB5LRkWNxBilCnjKWuJcdaPIXim8iqZKGbcY/DBzGUiS6sF475EIy38YPLU1XJTi7p E1Fne5zEB59tMz4AH6eYv0T+PXa8IVWMS1CDjXdDo7Xy0qPXldE86nNheZ3j6YtcBUwl i/NatJVpGPRIlHvmfp6GN5CeVgR14PLo9+ZowGkxLGmpsnnYxGN/J49yKbjUyaZbXiLK FnSg== X-Gm-Message-State: AOAM532SpqEULO/CfSlfBBLChT7HvkVMpCwsWVSG0JYWVzhDsmUroyLV QCyJ+Tc0thHZqxBpWAx6pdA= X-Google-Smtp-Source: ABdhPJy7DYuemMO8KiXVK3pNpUT2/ijFLO0TqkCZuWIR85RKHkLv+onyIggSkM2Lxu6LHD5nPGyXXg== X-Received: by 2002:a92:c60b:: with SMTP id p11mr21495771ilm.65.1630452244670; Tue, 31 Aug 2021 16:24:04 -0700 (PDT) Received: from localhost ([172.243.157.240]) by smtp.gmail.com with ESMTPSA id y11sm10516026iol.49.2021.08.31.16.24.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 31 Aug 2021 16:24:04 -0700 (PDT) Date: Tue, 31 Aug 2021 16:23:56 -0700 From: John Fastabend To: Lorenzo Bianconi , bpf@vger.kernel.org, netdev@vger.kernel.org Cc: lorenzo.bianconi@redhat.com, davem@davemloft.net, kuba@kernel.org, ast@kernel.org, daniel@iogearbox.net, shayagr@amazon.com, john.fastabend@gmail.com, dsahern@kernel.org, brouer@redhat.com, echaudro@redhat.com, jasowang@redhat.com, alexander.duyck@gmail.com, saeed@kernel.org, maciej.fijalkowski@intel.com, magnus.karlsson@intel.com, tirthendu.sarkar@intel.com, toke@redhat.com Message-ID: <612eba0cd2678_6b872081d@john-XPS-13-9370.notmuch> In-Reply-To: References: Subject: RE: [PATCH v12 bpf-next 03/18] net: mvneta: update mb bit before passing the xdp buffer to eBPF layer Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Lorenzo Bianconi wrote: > Update multi-buffer bit (mb) in xdp_buff to notify XDP/eBPF layer and > XDP remote drivers if this is a "non-linear" XDP buffer. Access > skb_shared_info only if xdp_buff mb is set in order to avoid possible > cache-misses. > > Signed-off-by: Lorenzo Bianconi > --- > drivers/net/ethernet/marvell/mvneta.c | 23 ++++++++++++++++++----- > 1 file changed, 18 insertions(+), 5 deletions(-) > > diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c > index 5d1007e1b5c9..9f4858e35566 100644 > --- a/drivers/net/ethernet/marvell/mvneta.c > +++ b/drivers/net/ethernet/marvell/mvneta.c > @@ -2037,9 +2037,14 @@ mvneta_xdp_put_buff(struct mvneta_port *pp, struct mvneta_rx_queue *rxq, > { > int i; > > + if (likely(!xdp_buff_is_mb(xdp))) > + goto out; > + Wouldn't nr_frags = 0 in the !xdp_buff_is_mb case? Is the xdp_buff_is_mb check with goto really required? > for (i = 0; i < sinfo->nr_frags; i++) > page_pool_put_full_page(rxq->page_pool, > skb_frag_page(&sinfo->frags[i]), true); > + > +out: > page_pool_put_page(rxq->page_pool, virt_to_head_page(xdp->data), > sync_len, true); > } > @@ -2241,7 +2246,6 @@ mvneta_swbm_rx_frame(struct mvneta_port *pp, > int data_len = -MVNETA_MH_SIZE, len; > struct net_device *dev = pp->dev; > enum dma_data_direction dma_dir; > - struct skb_shared_info *sinfo; > > if (*size > MVNETA_MAX_RX_BUF_SIZE) { > len = MVNETA_MAX_RX_BUF_SIZE; > @@ -2261,11 +2265,9 @@ mvneta_swbm_rx_frame(struct mvneta_port *pp, > > /* Prefetch header */ > prefetch(data); > + xdp_buff_clear_mb(xdp); > xdp_prepare_buff(xdp, data, pp->rx_offset_correction + MVNETA_MH_SIZE, > data_len, false); > - > - sinfo = xdp_get_shared_info_from_buff(xdp); > - sinfo->nr_frags = 0; > } > > static void > @@ -2299,6 +2301,9 @@ mvneta_swbm_add_rx_fragment(struct mvneta_port *pp, > skb_frag_off_set(frag, pp->rx_offset_correction); > skb_frag_size_set(frag, data_len); > __skb_frag_set_page(frag, page); > + > + if (!xdp_buff_is_mb(xdp)) > + xdp_buff_set_mb(xdp); > } else { > page_pool_put_full_page(rxq->page_pool, page, true); > } > @@ -2320,8 +2325,12 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct page_pool *pool, > struct xdp_buff *xdp, u32 desc_status) > { > struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp); > - int i, num_frags = sinfo->nr_frags; > struct sk_buff *skb; > + u8 num_frags; > + int i; > + > + if (unlikely(xdp_buff_is_mb(xdp))) > + num_frags = sinfo->nr_frags; > > skb = build_skb(xdp->data_hard_start, PAGE_SIZE); > if (!skb) > @@ -2333,6 +2342,9 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct page_pool *pool, > skb_put(skb, xdp->data_end - xdp->data); > skb->ip_summed = mvneta_rx_csum(pp, desc_status); > > + if (likely(!xdp_buff_is_mb(xdp))) > + goto out; > + Not that I care much, but couldn't you just init num_frags = 0 and avoid the goto? Anyways its not my driver so no need to change it if you like it better the way it is. Mostly just checking my understanding. > for (i = 0; i < num_frags; i++) { > skb_frag_t *frag = &sinfo->frags[i]; > > @@ -2341,6 +2353,7 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct page_pool *pool, > skb_frag_size(frag), PAGE_SIZE); > } > > +out: > return skb; > } > > -- > 2.31.1 >