From patchwork Mon May 29 16:12:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Gobert X-Patchwork-Id: 13258772 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4E7148F71 for ; Mon, 29 May 2023 16:13:03 +0000 (UTC) Received: from mail-wm1-x32d.google.com (mail-wm1-x32d.google.com [IPv6:2a00:1450:4864:20::32d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADF27A0; Mon, 29 May 2023 09:13:01 -0700 (PDT) Received: by mail-wm1-x32d.google.com with SMTP id 5b1f17b1804b1-3f6ffc2b314so9010075e9.0; Mon, 29 May 2023 09:13:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1685376780; x=1687968780; 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=Lmt1DO4BDFemx1g/90o2KUfvjpypOOLRqOoGdWC/rEY=; b=Uyv5LUD2AUAejN7H7ZhsgQTRk9NPT7CSQDzrj0uPseEpbtZp8XuFNglKAQ372rEWYi 3CL5sv5iwwY1c5Lwz1zMEO0mU6AQBhAGBFrCdxBSf2e1h1NrW1f9W0smI4mtPqgXrw+h 42bMsUh/G5PSIzDSH9y3tEXaqMhbQ6sbO3/JLvMkRLdyGjChL9nisZD9o3wrGn6Ukb8R 6eARZTwaLxgmnHg4cbFiywc3+vUVltsLftb70Rxpjc4ML0FpJo/18Y+yMRlP7RrrJz94 sTP0oykcQLpnjvasQWJWaNvE+hIBQ6SDGDWNpSGcrnkISCXhC6B90Cdr/wD5LFTdkavU +IFQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685376780; x=1687968780; 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=Lmt1DO4BDFemx1g/90o2KUfvjpypOOLRqOoGdWC/rEY=; b=YUhbdKrODivfGe32g6iBRODQRy/vkTH4F8KhJCAtBAseWv89RxjFsji14ibtGAQaP2 UrJEpdPHVSWBJb2x7CqEcijpqbBbG0oWCMExKHQV7OVG0gcsw9OOyN/tBnLQNS7709I2 FLwDASjTBuNOMEzgqB4xRWlcsATtNsHzyHaoMIn1pQjiRKmIzOb7nng+Bh/oG4R1tZhF 551Dl8hIBcmc5oEYeqD5aGbn2diRh4EiQ5sZv4nPwRMiAAOV58/VfAFO0CLvoE0eKp8t 03FA2dWHy8M/nuYMKjVmwsMTY11P7eKJjtG8nJYAuthrmhy8/vB31JsHUFiVIY1Skwbm Fv+w== X-Gm-Message-State: AC+VfDwZUbFl5sVBTthSdeY1QNdkp5bob9yRuOFcba4MKDwlhAjnLoWR Qe9IEuFxwmX0m+pz0snNqy4= X-Google-Smtp-Source: ACHHUZ6CJSWDfYfN7cgqr2lLNJllEBexqjagzgutYaffWOgHO4ReMIU6cneayLIv5AhoIrQfQbaK+A== X-Received: by 2002:a1c:7303:0:b0:3f4:fe7f:3d18 with SMTP id d3-20020a1c7303000000b003f4fe7f3d18mr6872577wmb.2.1685376780012; Mon, 29 May 2023 09:13:00 -0700 (PDT) Received: from debian ([89.238.191.199]) by smtp.gmail.com with ESMTPSA id k15-20020a05600c0b4f00b003f611b2aedesm14734431wmr.38.2023.05.29.09.12.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 May 2023 09:12:59 -0700 (PDT) Date: Mon, 29 May 2023 18:12:42 +0200 From: Richard Gobert To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, lixiaoyan@google.com, alexanderduyck@fb.com, linyunsheng@huawei.com, lucien.xin@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/1] gro: decrease size of CB Message-ID: <20230529161240.GA3958@debian> References: <20230529160503.GA3884@debian> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20230529160503.GA3884@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,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org 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 2d84165cb4f1..91454176a6d8 100644 --- a/net/core/gro.c +++ b/net/core/gro.c @@ -460,6 +460,14 @@ 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; @@ -489,7 +497,6 @@ 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; @@ -564,17 +571,13 @@ 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)) @@ -587,7 +590,8 @@ 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)