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[2620:137:e000::1:20]) by mx.google.com with ESMTP id q25-20020a639819000000b0042b4defce13si11466264pgd.344.2023.01.30.05.17.01; Mon, 30 Jan 2023 05:17:14 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20210112 header.b=gjRaS84Z; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235896AbjA3NFt (ORCPT + 99 others); Mon, 30 Jan 2023 08:05:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57612 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236738AbjA3NFn (ORCPT ); Mon, 30 Jan 2023 08:05:43 -0500 Received: from mail-wm1-x331.google.com (mail-wm1-x331.google.com [IPv6:2a00:1450:4864:20::331]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F39713D71; Mon, 30 Jan 2023 05:05:42 -0800 (PST) Received: by mail-wm1-x331.google.com with SMTP id q8so7937524wmo.5; Mon, 30 Jan 2023 05:05:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:to:from:date:from:to:cc:subject:date:message-id :reply-to; bh=7qD/pdat3Z43T3M0lNL9fDEciQ6LrvxQWEvx14VXeP8=; b=gjRaS84ZPKdBQsHb/ICv8kEYXFYmEjHkHmXCeve3hgG9v/Iqk8bmRpfaOFBCxKiYeo UO5tY1sgl/oO12Ix51KZjkcKCgsXaGOKH63W9/uKq/slY94spZJdiUVhn+gTwou5LitP wzSZimVl4Gn+6VT+lg4YkjW/rNdFq5pUUYXM8nRW103X/kukDppxTuvPKIPGchwbvd8p KoVUaFSmpr5LnktCFgQyipILZOiK4vODHdi/8FhsYiYczs6LTW69Ad5/Pjn5PppJa6db MmF/x0SOvnaADXNg76j41LCKwNRM8GfVNiaBfY3WFTmiI8YraP9ajB2wQs3YXsU7mX9+ EFbw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=7qD/pdat3Z43T3M0lNL9fDEciQ6LrvxQWEvx14VXeP8=; b=Ubo5WXw5qG4ajRFcygwMCTZCu/zpdZRIL7tMZQZPKVfCW5YJXC/nKLobqgHhJiEutj nXx7R2TcPktnJtPzNY2zHOW2IpvXY54hIlwxcXNlGyChNYPtmmdLNm7co8hIum+/utT0 L+dqVEEB6HfGcWH93QaqTO8UMA+l5xLvI56X8tBkMzE3PHvWiZAVpbApMyspU6vfymoJ 5uEBo68JNQe+odhptgtZLUVqkrP03lM45eWsQLVkMmrnn8tUPf8T/IHz9PxTlAV9eKhF HQa6+OuWde4dEUZv8nMGk7hEB1q+/Cb/GJa7uDKqhU9wDxh4M3NsDWjCaySX6+bCFZZN B4RA== X-Gm-Message-State: AO0yUKXrY12mPmetyViWqvLy5CixOTIuGfhmttIF5lgntmf7BJocVhkv v5wjgoMWQQpm2Iyf7sBl2/Y= X-Received: by 2002:a05:600c:4e89:b0:3dc:198c:dde with SMTP id f9-20020a05600c4e8900b003dc198c0ddemr20188150wmq.41.1675083940520; Mon, 30 Jan 2023 05:05:40 -0800 (PST) Received: from debian ([89.238.191.199]) by smtp.gmail.com with ESMTPSA id g8-20020adfe408000000b002bdda9856b5sm11991793wrm.50.2023.01.30.05.05.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Jan 2023 05:05:40 -0800 (PST) Date: Mon, 30 Jan 2023 14:05:11 +0100 From: Richard Gobert To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, yoshfuji@linux-ipv6.org, dsahern@kernel.org, steffen.klassert@secunet.com, lixiaoyan@google.com, alexanderduyck@fb.com, leon@kernel.org, ye.xingchen@zte.com.cn, iwienand@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] gro: decrease size of CB Message-ID: <20230130130509.GA7974@debian> References: <20230130130047.GA7913@debian> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20230130130047.GA7913@debian> User-Agent: Mutt/1.10.1 (2018-07-13) X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1756453545267629402?= X-GMAIL-MSGID: =?utf-8?q?1756453545267629402?= The GRO control block (NAPI_GRO_CB) is currently at its maximum size. This commit reduces its size by putting two groups of fields that are used only at different times into a union. Specifically, the fields frag0 and frag0_len are the fields that make up the frag0 optimisation mechanism, which is used during the initial parsing of the SKB. The fields last and age are used after the initial parsing, while the SKB is stored in the GRO list, waiting for other packets to arrive. There was one location in dev_gro_receive that modified the frag0 fields after setting last and age. I changed this accordingly without altering the code behaviour. Signed-off-by: Richard Gobert --- include/net/gro.h | 26 ++++++++++++++++---------- net/core/gro.c | 18 +++++++++++------- 2 files changed, 27 insertions(+), 17 deletions(-) diff --git a/include/net/gro.h b/include/net/gro.h index a4fab706240d..7b47dd6ce94f 100644 --- a/include/net/gro.h +++ b/include/net/gro.h @@ -11,11 +11,23 @@ #include struct napi_gro_cb { - /* Virtual address of skb_shinfo(skb)->frags[0].page + offset. */ - void *frag0; + union { + struct { + /* Virtual address of skb_shinfo(skb)->frags[0].page + offset. */ + void *frag0; - /* Length of frag0. */ - unsigned int frag0_len; + /* Length of frag0. */ + unsigned int frag0_len; + }; + + struct { + /* used in skb_gro_receive() slow path */ + struct sk_buff *last; + + /* jiffies when first packet was created/queued */ + unsigned long age; + }; + }; /* This indicates where we are processing relative to skb->data. */ int data_offset; @@ -32,9 +44,6 @@ struct napi_gro_cb { /* Used in ipv6_gro_receive() and foo-over-udp */ u16 proto; - /* jiffies when first packet was created/queued */ - unsigned long age; - /* Used in napi_gro_cb::free */ #define NAPI_GRO_FREE 1 #define NAPI_GRO_FREE_STOLEN_HEAD 2 @@ -77,9 +86,6 @@ struct napi_gro_cb { /* used to support CHECKSUM_COMPLETE for tunneling protocols */ __wsum csum; - - /* used in skb_gro_receive() slow path */ - struct sk_buff *last; }; #define NAPI_GRO_CB(skb) ((struct napi_gro_cb *)(skb)->cb) diff --git a/net/core/gro.c b/net/core/gro.c index 506f83d715f8..869823d9e8bc 100644 --- a/net/core/gro.c +++ b/net/core/gro.c @@ -449,6 +449,14 @@ static void gro_pull_from_frag0(struct sk_buff *skb, int grow) } } +static inline void gro_try_pull_from_frag0(struct sk_buff *skb) +{ + int grow = skb_gro_offset(skb) - skb_headlen(skb); + + if (grow > 0) + gro_pull_from_frag0(skb, grow); +} + static void gro_flush_oldest(struct napi_struct *napi, struct list_head *head) { struct sk_buff *oldest; @@ -478,7 +486,6 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff struct sk_buff *pp = NULL; enum gro_result ret; int same_flow; - int grow; if (netif_elide_gro(skb->dev)) goto normal; @@ -553,17 +560,13 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff else gro_list->count++; + gro_try_pull_from_frag0(skb); NAPI_GRO_CB(skb)->age = jiffies; NAPI_GRO_CB(skb)->last = skb; if (!skb_is_gso(skb)) skb_shinfo(skb)->gso_size = skb_gro_len(skb); list_add(&skb->list, &gro_list->list); ret = GRO_HELD; - -pull: - grow = skb_gro_offset(skb) - skb_headlen(skb); - if (grow > 0) - gro_pull_from_frag0(skb, grow); ok: if (gro_list->count) { if (!test_bit(bucket, &napi->gro_bitmask)) @@ -576,7 +579,8 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff normal: ret = GRO_NORMAL; - goto pull; + gro_try_pull_from_frag0(skb); + goto ok; } struct packet_offload *gro_find_receive_by_type(__be16 type)