From patchwork Mon Jan 30 13:05:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Gobert X-Patchwork-Id: 13121066 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3DC1DC636CD for ; Mon, 30 Jan 2023 13:05:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236100AbjA3NFq (ORCPT ); Mon, 30 Jan 2023 08:05:46 -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-Google-Smtp-Source: AK7set8M0nolg+58fdwYoXjuZbZphOzYytqNq4z7jpZnZAViEEs+St5afR9bzdAvMMNfZXJufBsOJw== 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) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 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) From patchwork Mon Jan 30 13:07:55 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Gobert X-Patchwork-Id: 13121076 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95DF9C54EED for ; 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Mon, 30 Jan 2023 05:08:24 -0800 (PST) Received: from debian ([89.238.191.199]) by smtp.gmail.com with ESMTPSA id 2-20020a05600c028200b003dc4baaedd3sm7282532wmk.37.2023.01.30.05.08.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Jan 2023 05:08:24 -0800 (PST) Date: Mon, 30 Jan 2023 14:07:55 +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 2/2] gro: optimise redundant parsing of packets Message-ID: <20230130130752.GA8015@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) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Currently, the IPv6 extension headers are parsed twice: first in ipv6_gro_receive, and then again in ipv6_gro_complete. The field NAPI_GRO_CB(skb)->proto is used by GRO to hold the layer 4 protocol type that comes after the IPv6 layer. I noticed that it is set in ipv6_gro_receive, but isn't used anywhere. By using this field, and also storing the size of the network header, we can avoid parsing extension headers a second time in ipv6_gro_complete. The implementation had to handle both inner and outer layers in case of encapsulation (as they can't use the same field). I've applied this optimisation to all base protocols (IPv6, IPv4, Ethernet). Then, I benchmarked this patch on my machine, using ftrace to measure ipv6_gro_complete's performance, and there was an improvement. Signed-off-by: Richard Gobert --- include/net/gro.h | 8 ++++++-- net/ethernet/eth.c | 11 +++++++++-- net/ipv4/af_inet.c | 8 +++++++- net/ipv6/ip6_offload.c | 15 ++++++++++++--- 4 files changed, 34 insertions(+), 8 deletions(-) diff --git a/include/net/gro.h b/include/net/gro.h index 7b47dd6ce94f..d364616cb930 100644 --- a/include/net/gro.h +++ b/include/net/gro.h @@ -41,8 +41,8 @@ struct napi_gro_cb { /* Number of segments aggregated. */ u16 count; - /* Used in ipv6_gro_receive() and foo-over-udp */ - u16 proto; + /* Used in eth_gro_receive() */ + __be16 network_proto; /* Used in napi_gro_cb::free */ #define NAPI_GRO_FREE 1 @@ -86,6 +86,10 @@ struct napi_gro_cb { /* used to support CHECKSUM_COMPLETE for tunneling protocols */ __wsum csum; + + /* Used in inet and ipv6 _gro_receive() */ + u16 network_len; + u8 transport_proto; }; #define NAPI_GRO_CB(skb) ((struct napi_gro_cb *)(skb)->cb) diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c index 2edc8b796a4e..d68ad90f0a9e 100644 --- a/net/ethernet/eth.c +++ b/net/ethernet/eth.c @@ -439,6 +439,9 @@ struct sk_buff *eth_gro_receive(struct list_head *head, struct sk_buff *skb) goto out; } + if (!NAPI_GRO_CB(skb)->encap_mark) + NAPI_GRO_CB(skb)->network_proto = type; + skb_gro_pull(skb, sizeof(*eh)); skb_gro_postpull_rcsum(skb, eh, sizeof(*eh)); @@ -456,12 +459,16 @@ EXPORT_SYMBOL(eth_gro_receive); int eth_gro_complete(struct sk_buff *skb, int nhoff) { struct ethhdr *eh = (struct ethhdr *)(skb->data + nhoff); - __be16 type = eh->h_proto; + __be16 type; struct packet_offload *ptype; int err = -ENOSYS; - if (skb->encapsulation) + if (skb->encapsulation) { skb_set_inner_mac_header(skb, nhoff); + type = eh->h_proto; + } else { + type = NAPI_GRO_CB(skb)->network_proto; + } ptype = gro_find_complete_by_type(type); if (ptype != NULL) diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 6c0ec2789943..4401af7b3a15 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1551,6 +1551,9 @@ struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb) * immediately following this IP hdr. */ + if (!NAPI_GRO_CB(skb)->encap_mark) + NAPI_GRO_CB(skb)->transport_proto = proto; + /* Note : No need to call skb_gro_postpull_rcsum() here, * as we already checked checksum over ipv4 header was 0 */ @@ -1621,12 +1624,15 @@ int inet_gro_complete(struct sk_buff *skb, int nhoff) __be16 newlen = htons(skb->len - nhoff); struct iphdr *iph = (struct iphdr *)(skb->data + nhoff); const struct net_offload *ops; - int proto = iph->protocol; + int proto; int err = -ENOSYS; if (skb->encapsulation) { skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP)); skb_set_inner_network_header(skb, nhoff); + proto = iph->protocol; + } else { + proto = NAPI_GRO_CB(skb)->transport_proto; } csum_replace2(&iph->check, iph->tot_len, newlen); diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c index 00dc2e3b0184..79ba5882f576 100644 --- a/net/ipv6/ip6_offload.c +++ b/net/ipv6/ip6_offload.c @@ -227,11 +227,14 @@ INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head, iph = ipv6_hdr(skb); } - NAPI_GRO_CB(skb)->proto = proto; - flush--; nlen = skb_network_header_len(skb); + if (!NAPI_GRO_CB(skb)->encap_mark) { + NAPI_GRO_CB(skb)->transport_proto = proto; + NAPI_GRO_CB(skb)->network_len = nlen; + } + list_for_each_entry(p, head, list) { const struct ipv6hdr *iph2; __be32 first_word; /* */ @@ -358,7 +361,13 @@ INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff) iph->payload_len = htons(payload_len); } - nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops); + if (!skb->encapsulation) { + ops = rcu_dereference(inet6_offloads[NAPI_GRO_CB(skb)->transport_proto]); + nhoff += NAPI_GRO_CB(skb)->network_len; + } else { + nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops); + } + if (WARN_ON(!ops || !ops->callbacks.gro_complete)) goto out;