From patchwork Mon Mar 25 18:25:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Gobert X-Patchwork-Id: 13602743 Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) (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 1DBDB4779D; Mon, 25 Mar 2024 18:27:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.54 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711391244; cv=none; b=i8dMGc7pym4hG3/4OOe+W9G658hzvi+d4KXOo+uRpe5mhVtHJ3PqesQo/qrtaaTJChXReHv47F+nN7zzoMslr85cTVn3i1mN4QHlwJfQpaMc3Ys1sapdEmqOP7uEEyH7f6pofaf1nE+bbXDSFm/1NjPy6b+sbUpqb4nBxIAdHTk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711391244; c=relaxed/simple; bh=zPeew8jBAPw+CqVIPr+fTbu7R6EL+mUFdchKxCVilOk=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Ct/dvINXpojnxbiHgkgJmQ2p1Z7oAKr5mfcvW9OqR3IYO8LAW4xRn5srVmbl3pYigEJOPbx/P0D2LOrfqw6Hq70QG2+1tRNj5SB/0tT5j4zAJYmeEAUVGpxaajDr/4g7Wx/Hb5xgq6CNOlYQPM9NwJxFLtXpxzE7nwkuncXWK1Y= 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=hv7vYH+6; arc=none smtp.client-ip=209.85.128.54 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="hv7vYH+6" Received: by mail-wm1-f54.google.com with SMTP id 5b1f17b1804b1-41488e17e1cso6985135e9.0; Mon, 25 Mar 2024 11:27:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1711391240; x=1711996040; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:from:to:cc:subject:date:message-id :reply-to; bh=6BZhEnyWpNsK0BBdDmmAssPA7emcAcdAM4PGsihwRu0=; b=hv7vYH+63RlV217RakwJg4Nnv1Fn81qaGwMX3/FQVOic1lGAIsCWapp+DWwVrRP1ns emZl8lO8fRs66BCxS1foW837jGL7qJiAHGTrg0HA7jVJfMuLzAat2hQ3qTrthWKwgLEZ Ok/qxe10ltscJ0766oDM9Dh0uWXWyk7Ck+XrByJFavvNCjJot7eDtLC8IZK9r0D+xloH 0lWkVhjh5ODI6jEhsc05QepRUGOEZ9maoAP5N+1UEl6vz9XM3+wiP+IREXvHRYi3ZCTC OqgxREnEuvjAa9rl8CbL78ImJDV1+4Prf2ZQYtCSgTg6Ws+rLte4+7Nq9pU7K0ukDGkm l9SA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1711391240; x=1711996040; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=6BZhEnyWpNsK0BBdDmmAssPA7emcAcdAM4PGsihwRu0=; b=d3/0ej51MKF0dNtCnx5ZNOdoOl6dNd8m2C4d/UZ5tdiHNupcz/bIbAHq7JkFUlBQrS 5hi41x6dYoOMQOelQg2Phy97eKVtmowACqtf4U6gjlIUL/gr76NGvalm7tCMxjWSgk6t sI3JIRXyuRzrpg10sJ8QW6ZrEdCkQlME5T8GutyfDSjVIuPiRPeninwU1e9Fd4kuSeof gruJXyrRS/aSaxVthfhHgYBVNXAHsV8qDSJqFGl2oc4uPxEb3SUW0tVuaj0NoLi0aPtD ulHZQDeMKQu0OKowl3CuUoJ/HCZL+Iv+kXyS8puTMTdM0kGiBJ9rE3wHt3s7tOjhlH3k v4tg== X-Forwarded-Encrypted: i=1; AJvYcCVJ+hM7zvLDNSPHiUmLhRGHBo8yoDpnJTXjZW11C/ZtaWksyEH5dY2h+VtX+4sqBym/Ng8NlVS+dhSRe39KbqBdMMYouPtmiH5qRWibQIsDc+Z0N/EVYpCIh2PUNSUSdO9UBtKfuMTlLnm+cYhmmNnNUHlzyMABKt6FsqxCP0mXKsf0E4qj X-Gm-Message-State: AOJu0Yy5uYjXfKpPcAihbcs9DFfoaGDhOFWJbXs5Ro+v0UPnw3er5PR4 pWdlwlDabJa08J/SUZsOSgUMSJt71LjSBhUhgQ/xxt6tAAqMRTIL X-Google-Smtp-Source: AGHT+IGw2FyfG4pSRuTSSctf5dkimTl69ohf54hrclbjflJbxFgzV67IYwdAtL3tkviQC/nF97DVjQ== X-Received: by 2002:a05:600c:5120:b0:414:65cb:7e99 with SMTP id o32-20020a05600c512000b0041465cb7e99mr309841wms.26.1711391240337; Mon, 25 Mar 2024 11:27:20 -0700 (PDT) Received: from localhost ([146.70.204.204]) by smtp.gmail.com with ESMTPSA id m29-20020a05600c3b1d00b004147b5dd6f8sm9258475wms.9.2024.03.25.11.27.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 25 Mar 2024 11:27:20 -0700 (PDT) From: Richard Gobert 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, amcohen@nvidia.com, petrm@nvidia.com, jbenc@redhat.com, bpoirier@nvidia.com, b.galvani@gmail.com, liujian56@huawei.com, horms@kernel.org, linyunsheng@huawei.com, richardbgobert@gmail.com, therbert@google.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH net-next v4 4/4] net: gro: move L3 flush checks to tcp_gro_receive Date: Mon, 25 Mar 2024 19:25:43 +0100 Message-Id: <20240325182543.87683-5-richardbgobert@gmail.com> In-Reply-To: <20240325182543.87683-1-richardbgobert@gmail.com> References: <20240325182543.87683-1-richardbgobert@gmail.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 {inet,ipv6}_gro_receive functions perform flush checks (ttl, flags, iph->id, ...) against all packets in a loop. These flush checks are used currently only in tcp flows in GRO. These checks 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 declarative 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 a1cc8e8c2ebd..73e266194528 100644 --- a/include/net/gro.h +++ b/include/net/gro.h @@ -36,15 +36,15 @@ 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 @@ -85,9 +85,6 @@ 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 7c468ed805f4..f8cbc08197f7 100644 --- a/net/core/gro.c +++ b/net/core/gro.c @@ -329,8 +329,6 @@ 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; @@ -470,7 +468,6 @@ 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 6546bf376b24..9d7fd79ee915 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1513,7 +1513,6 @@ 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; @@ -1530,43 +1529,8 @@ 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 a63af9a6b0f7..ed9947bb903d 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 incrementing 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 ba41939537f2..c9a6bc1afc9a 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);