From patchwork Sat Mar 9 15:34:53 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Gobert X-Patchwork-Id: 13587701 Received: from mail-wm1-f43.google.com (mail-wm1-f43.google.com [209.85.128.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A5A123BBCC; Sat, 9 Mar 2024 15:35:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.43 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709998514; cv=none; b=kPomwjoONXqANUhdOynRdEz8621VctlCGKHjizQOjtG1OK7NFrFYR3tNHOC7C3xeNG7hmN4m9shUhYk4aMtDjlUqP8Odk0M+6LdfNCHB0jfQXFQMsmhyPfnTNULw5fi9XTXplG+yZh4CLRkCQjCR3+DYgFqpCpAq92tDWjC58WY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709998514; c=relaxed/simple; bh=LlXnxtaYIM9zfwx7U2jZVAwynJNW2FZS5Ovo3PqDSiA=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=gh+tsW+lW5huDZfyT/U/hZ5jH2tbFackKqLIgzjyLGcZTDTnw6w5ef0J6nF4wZfGsjcpvMMcrCl6vJWunh47D/Hl5Ad+GM7iUKHIwIem8VJMLtbkjVm70h+DhXL1vCPLZplZWrkCV19st+QbvcctSGlao5Ge6147P/UlIc3elBU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=CzoS3RaS; arc=none smtp.client-ip=209.85.128.43 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="CzoS3RaS" Received: by mail-wm1-f43.google.com with SMTP id 5b1f17b1804b1-4131ad76f05so9876455e9.0; Sat, 09 Mar 2024 07:35:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1709998511; x=1710603311; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:references:to:subject :mime-version:date:message-id:from:to:cc:subject:date:message-id :reply-to; bh=gJAtax3ZwpbB1qeVzq9Rm9GeuFxipf4n1zk7zLFbVLY=; b=CzoS3RaS/ehJnmua9Nu6jUFhJtP57dEgZPWt3z0iqbw/9Bk3LQx5Rq9vNTCqX0f7eh Vvj9VOxf5qsFsPejVE44ecjMlPyxHXv2a8/br2T2u4OOB7IxoC2JXPCnZlTq3AOM/2+w G+THY9XjSWXVR53XT2rdL+LKJxRrafKX71XgLlQsdDyUf7iAS9KExIWESnv69E6fbN90 IcPK+XHpJvVD03hDdRLP76eyGmqxNSCyPQ78cSLPRYeJKMMRIXAunKK7Ia+5n7AI7HUU 0k+g7jikgAtvsklQqH7HMu9ndb2N+rq2tXORFk8ltdfEZYnMKHT4KfIcFU4lmraDvFvb m8bA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709998511; x=1710603311; h=content-transfer-encoding:in-reply-to:from:references:to:subject :mime-version:date:message-id:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=gJAtax3ZwpbB1qeVzq9Rm9GeuFxipf4n1zk7zLFbVLY=; b=hwtFNG4OCoK3pTVRE9grpf/7jhQXMD7N1CoRgpxFcjWiTSMuJkUwoW1UBRWpqENR8L uWKmlguXBwUC5fTJPENgNemIHIvO9klQPGAWAIMfP+A/YNhzW4KNWMldVuPcunLfNd6C NDfXiyLaIscNrbLZXCA/eN9ES8Wd8uVD3AsyLcS5gCStjbSlArqmjzHACPDP/IlsdnSC 644JppvVYqZEndmyC7MdlKIDIc8V2H90YLEjq8c/anl6o8V09FgMbm/n8A1WtguevXE9 YzyyWo6bupoG0UjAda1dTorsITtO1rbT0TxIwZzFrPY+q/ULxIW4aP3b9v9uGfEYjSf0 ABew== X-Forwarded-Encrypted: i=1; AJvYcCV5uw0xNa/BOpBbb+5Hdgya4+RlUnycd5j2ki8b4FU0PgZdbmig9tkpb7mp38ONKays7OrqSHj9b7y+GqOSQw0x+HG1L6ZpS/7X13N6MMzxTI3payly/I+bpVK5apZFiw50FTnK8W8k0aRYmYSTY3Ewi+4mVpn9tskeILG+66eNiQ55hOHe X-Gm-Message-State: AOJu0Yw3CeaATtt9adc8+Qgh/4JFTNLp8Z+IY22MP00nu7J/dUn2q31e 3ZaY6H2s2aZQH4BfSMsZ8DtG38Eg5hS0M6I0QUMXdOTRZ5yKp1jS X-Google-Smtp-Source: AGHT+IFn8SaOca0RymiIDlqkgScGUDw5Em/8plmTmdQzFSr2cjxCVa4qSL07HNhtkWZFlCRxFWlclg== X-Received: by 2002:a05:600c:34c7:b0:413:1741:2a21 with SMTP id d7-20020a05600c34c700b0041317412a21mr1957298wmq.1.1709998510824; Sat, 09 Mar 2024 07:35:10 -0800 (PST) Received: from debian ([146.70.204.204]) by smtp.gmail.com with ESMTPSA id n30-20020a05600c501e00b0041313d4c852sm2865312wmr.19.2024.03.09.07.35.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 09 Mar 2024 07:35:10 -0800 (PST) Message-ID: <88831c36-a589-429f-8e8b-2ecb66a30263@gmail.com> Date: Sat, 9 Mar 2024 16:34:53 +0100 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: [PATCH net-next v3 4/4] net: gro: move L3 flush checks to tcp_gro_receive To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, willemdebruijn.kernel@gmail.com, dsahern@kernel.org, xeb@mail.ru, shuah@kernel.org, idosch@nvidia.com, razor@blackwall.org, amcohen@nvidia.com, petrm@nvidia.com, jbenc@redhat.com, bpoirier@nvidia.com, b.galvani@gmail.com, gavinl@nvidia.com, liujian56@huawei.com, horms@kernel.org, linyunsheng@huawei.com, therbert@google.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org References: From: Richard Gobert In-Reply-To: {inet,ipv6}_gro_receive functions perform flush checks (ttl, flags, iph->id, ...) against all packets in a loop. These flush checks are relevant only to tcp flows, and as such they're used to determine whether the packets can be merged later in tcp_gro_receive. These checks are not relevant to UDP packets. Furthermore, they need to be done only once in tcp_gro_receive and only against the found p skb, since they only affect flush and not same_flow. Levaraging the previous commit in the series, in which correct network header offsets are saved for both outer and inner network headers - allowing these checks to be done only once, in tcp_gro_receive. As a result, NAPI_GRO_CB(p)->flush is not used at all. In addition - flush_id checks are more declerative and contained in inet_gro_flush, thus removing the need for flush_id in napi_gro_cb. This results in less parsing code for UDP flows and non-loop flush tests for TCP flows. For example, running 40 IP/UDP netperf connections: ./super_netperf.sh 40 -H 1.1.1.2 -t UDP_STREAM -l 120 Running perf top for 90s we can see that relatively less time is spent on inet_gro_receive when GRO is not coalescing UDP: net-next: 1.26% [kernel] [k] inet_gro_receive patch applied: 0.85% [kernel] [k] inet_gro_receive udpgro_bench.sh single connection GRO improvement: net-next: 0.76% [kernel] [k] inet_gro_receive patch applied: 0.61% [kernel] [k] inet_gro_receive Signed-off-by: Richard Gobert --- include/net/gro.h | 9 ++---- net/core/gro.c | 3 -- net/ipv4/af_inet.c | 36 --------------------- net/ipv4/tcp_offload.c | 72 ++++++++++++++++++++++++++++++++++-------- net/ipv6/ip6_offload.c | 11 ------- 5 files changed, 62 insertions(+), 69 deletions(-) diff --git a/include/net/gro.h b/include/net/gro.h index 9d1389269509..34e50f77f744 100644 --- a/include/net/gro.h +++ b/include/net/gro.h @@ -35,15 +35,15 @@ struct napi_gro_cb { /* This is non-zero if the packet cannot be merged with the new skb. */ u16 flush; - /* Save the IP ID here and check when we get to the transport layer */ - u16 flush_id; - /* Number of segments aggregated. */ u16 count; /* Used in ipv6_gro_receive() and foo-over-udp and esp-in-udp */ u16 proto; + /* used to support CHECKSUM_COMPLETE for tunneling protocols */ + __wsum csum; + /* Used in napi_gro_cb::free */ #define NAPI_GRO_FREE 1 #define NAPI_GRO_FREE_STOLEN_HEAD 2 @@ -84,9 +84,6 @@ struct napi_gro_cb { u8 is_flist:1; ); - /* used to support CHECKSUM_COMPLETE for tunneling protocols */ - __wsum csum; - /* L3 offsets */ union { struct { diff --git a/net/core/gro.c b/net/core/gro.c index 2b42138f816c..128d7b9c8dfb 100644 --- a/net/core/gro.c +++ b/net/core/gro.c @@ -332,8 +332,6 @@ static void gro_list_prepare(const struct list_head *head, list_for_each_entry(p, head, list) { unsigned long diffs; - NAPI_GRO_CB(p)->flush = 0; - if (hash != skb_get_hash_raw(p)) { NAPI_GRO_CB(p)->same_flow = 0; continue; @@ -473,7 +471,6 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff sizeof(u32))); /* Avoid slow unaligned acc */ *(u32 *)&NAPI_GRO_CB(skb)->zeroed = 0; NAPI_GRO_CB(skb)->flush = skb_has_frag_list(skb); - NAPI_GRO_CB(skb)->is_atomic = 1; NAPI_GRO_CB(skb)->count = 1; if (unlikely(skb_is_gso(skb))) { NAPI_GRO_CB(skb)->count = skb_shinfo(skb)->gso_segs; diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index c6bb21c27aee..5b74c6d2ed8b 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1512,7 +1512,6 @@ struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb) list_for_each_entry(p, head, list) { struct iphdr *iph2; - u16 flush_id; if (!NAPI_GRO_CB(p)->same_flow) continue; @@ -1529,43 +1528,8 @@ struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb) NAPI_GRO_CB(p)->same_flow = 0; continue; } - - /* All fields must match except length and checksum. */ - NAPI_GRO_CB(p)->flush |= - (iph->ttl ^ iph2->ttl) | - (iph->tos ^ iph2->tos) | - ((iph->frag_off ^ iph2->frag_off) & htons(IP_DF)); - - NAPI_GRO_CB(p)->flush |= flush; - - /* We need to store of the IP ID check to be included later - * when we can verify that this packet does in fact belong - * to a given flow. - */ - flush_id = (u16)(id - ntohs(iph2->id)); - - /* This bit of code makes it much easier for us to identify - * the cases where we are doing atomic vs non-atomic IP ID - * checks. Specifically an atomic check can return IP ID - * values 0 - 0xFFFF, while a non-atomic check can only - * return 0 or 0xFFFF. - */ - if (!NAPI_GRO_CB(p)->is_atomic || - !(iph->frag_off & htons(IP_DF))) { - flush_id ^= NAPI_GRO_CB(p)->count; - flush_id = flush_id ? 0xFFFF : 0; - } - - /* If the previous IP ID value was based on an atomic - * datagram we can overwrite the value and ignore it. - */ - if (NAPI_GRO_CB(skb)->is_atomic) - NAPI_GRO_CB(p)->flush_id = flush_id; - else - NAPI_GRO_CB(p)->flush_id |= flush_id; } - NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF)); NAPI_GRO_CB(skb)->flush |= flush; /* Note : No need to call skb_gro_postpull_rcsum() here, diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c index fde800179b2e..c165e72555e1 100644 --- a/net/ipv4/tcp_offload.c +++ b/net/ipv4/tcp_offload.c @@ -178,6 +178,55 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb, return segs; } +static int inet_gro_flush(const struct iphdr *iph, const struct iphdr *iph2, + struct sk_buff *p, u32 outer) +{ + const u32 id = ntohl(*(__be32 *)&iph->id); + const u32 id2 = ntohl(*(__be32 *)&iph2->id); + const int flush_id = ntohs(id >> 16) - ntohs(id2 >> 16); + const u16 count = NAPI_GRO_CB(p)->count; + const u32 df = id & IP_DF; + u32 is_atomic; + int flush; + + /* All fields must match except length and checksum. */ + flush = (iph->ttl ^ iph2->ttl) | (iph->tos ^ iph2->tos) | (df ^ (id2 & IP_DF)); + + /* When we receive our second frame we can make a decision on if we + * continue this flow as an atomic flow with a fixed ID or if we use + * an incremdfenting ID. + */ + if (count == 1) { + is_atomic = df && flush_id == 0; + NAPI_GRO_CB(p)->is_atomic = is_atomic; + } else { + is_atomic = df && NAPI_GRO_CB(p)->is_atomic; + } + + /* Ignore outer IP ID value if based on atomic datagram. */ + outer = (outer && df) - 1; + is_atomic--; + + return flush | ((flush_id ^ (count & is_atomic)) & outer); +} + +static int ipv6_gro_flush(const struct ipv6hdr *iph, const struct ipv6hdr *iph2) +{ + /* */ + __be32 first_word = *(__be32 *)iph ^ *(__be32 *)iph2; + + /* Flush if Traffic Class fields are different. */ + return (first_word & htonl(0x0FF00000)) | + (__force __be32)(iph->hop_limit ^ iph2->hop_limit); +} + +static int gro_network_flush(const void *nh, const void *nh2, + struct sk_buff *p, u32 outer) +{ + return (((struct iphdr *)nh)->version == 6) ? ipv6_gro_flush(nh, nh2) : + inet_gro_flush(nh, nh2, p, outer); +} + struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb) { struct sk_buff *pp = NULL; @@ -190,6 +239,7 @@ struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb) unsigned int mss = 1; unsigned int hlen; unsigned int off; + bool encap_mark; int flush = 1; int i; @@ -232,9 +282,7 @@ struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb) goto out_check_final; found: - /* Include the IP ID check below from the inner most IP hdr */ - flush = NAPI_GRO_CB(p)->flush; - flush |= (__force int)(flags & TCP_FLAG_CWR); + flush = (__force int)(flags & TCP_FLAG_CWR); flush |= (__force int)((flags ^ tcp_flag_word(th2)) & ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH)); flush |= (__force int)(th->ack_seq ^ th2->ack_seq); @@ -242,16 +290,14 @@ struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb) flush |= *(u32 *)((u8 *)th + i) ^ *(u32 *)((u8 *)th2 + i); - /* When we receive our second frame we can made a decision on if we - * continue this flow as an atomic flow with a fixed ID or if we use - * an incrementing ID. - */ - if (NAPI_GRO_CB(p)->flush_id != 1 || - NAPI_GRO_CB(p)->count != 1 || - !NAPI_GRO_CB(p)->is_atomic) - flush |= NAPI_GRO_CB(p)->flush_id; - else - NAPI_GRO_CB(p)->is_atomic = false; + encap_mark = NAPI_GRO_CB(skb)->encap_mark; + for (i = 0; i <= encap_mark; i++) { + const u16 diff = off - NAPI_GRO_CB(skb)->network_offsets[i]; + + flush |= gro_network_flush((void *)th - diff, + (void *)th2 - diff, + p, i != encap_mark); + } mss = skb_shinfo(p)->gso_size; diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c index d9d3a6bed510..b1850c20d799 100644 --- a/net/ipv6/ip6_offload.c +++ b/net/ipv6/ip6_offload.c @@ -288,19 +288,8 @@ INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head, nlen - sizeof(struct ipv6hdr))) goto not_same_flow; } - /* flush if Traffic Class fields are different */ - NAPI_GRO_CB(p)->flush |= !!((first_word & htonl(0x0FF00000)) | - (__force __be32)(iph->hop_limit ^ iph2->hop_limit)); - NAPI_GRO_CB(p)->flush |= flush; - - /* If the previous IP ID value was based on an atomic - * datagram we can overwrite the value and ignore it. - */ - if (NAPI_GRO_CB(skb)->is_atomic) - NAPI_GRO_CB(p)->flush_id = 0; } - NAPI_GRO_CB(skb)->is_atomic = true; NAPI_GRO_CB(skb)->flush |= flush; skb_gro_postpull_rcsum(skb, iph, nlen);