From mboxrd@z Thu Jan 1 00:00:00 1970 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 648B879E5 for ; Sun, 29 Oct 2023 07:52:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="4riE/LWW" Received: from mail-pj1-x104a.google.com (mail-pj1-x104a.google.com [IPv6:2607:f8b0:4864:20::104a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BA6F4D6 for ; Sun, 29 Oct 2023 00:52:50 -0700 (PDT) Received: by mail-pj1-x104a.google.com with SMTP id 98e67ed59e1d1-27d56564684so3447022a91.2 for ; Sun, 29 Oct 2023 00:52:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1698565970; x=1699170770; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=KLSV0t/MTtVgP7bk5okHqiivsagnjynn9u5/BnTVmVI=; b=4riE/LWWgIMGIuPT8/WiWf1suqttmcJJJ0gGmoNvEp/pHJ3HVIWNo0VZUOQhNzHV/D ib87NOxvdfBOagUqBnqRKlFJ0M3nt6h3EuAb0kWRMLU0iMHc/BlAlMAmIC0eaV7qRpyg iO323Vlei2/T9/EJQBe3hl0ssiM/pHbd/m4sCHcFpBpntpLLPqjzzE74a3/EmwiVe3mx an1t5pI41m3i2waMucPaZskbU5MlDJqpo4d+H3mTHIw0XErWDZiK/9vEjZN9VpaAlEM/ gpBHnvf3SpkYUeebQPlUNxqbzvBIsig0KKprTwGENQUZZF33R9wGG7bjKqVB+h0HsuzJ qHSw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698565970; x=1699170770; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=KLSV0t/MTtVgP7bk5okHqiivsagnjynn9u5/BnTVmVI=; b=De7+/jxSvCgRizsD1BIZNSckbF9JVu2CxgX1TPSez7VeGE250PbcW2GuXDb6QlYZt7 WwelST/rErKTHIzH+dsdwxsHZQVtpsnmPfDRSLljQgznDam7wXb0eu3hskCOHcFTznAy QlfKvUZJq+Ic9/giHkt4opQ/ml9+jx+WyH9bxJwl0fXP/X0L6NtIsWlz1Q90XdlwoYCa h8wyvIKW5m477Omb3GNwW2OsZ2Ep3U0/3M9st6lKl5gT4VWotUyyNMMSGth5WBFN+vch p4+ieWSFSL7yvgOELStMJGWOQtomcipRJN6J0eUxmUlU0SM6q4TQKGsBnCGR2lehyXHQ /P7g== X-Gm-Message-State: AOJu0YyB1Y2OJhmR2fYZT9TSdyYvS02SNJqIjSrhqEsAW8N2Qr40Cs/N 6UVQwz3OZupXSIwl+GniAlI+RwXy7NkniCA= X-Google-Smtp-Source: AGHT+IHGFtYfBhnld+5eQNYm5J1gcOOqGLeaUL/ggRf4IBZALSeThonbop8waDD9UZsP1GhGTmbxztea/Pfd0mo= X-Received: from coco0920.c.googlers.com ([fda3:e722:ac3:cc00:20:ed76:c0a8:2a23]) (user=lixiaoyan job=sendgmr) by 2002:a17:903:454:b0:1cc:3f29:2904 with SMTP id iw20-20020a170903045400b001cc3f292904mr22453plb.7.1698565970086; Sun, 29 Oct 2023 00:52:50 -0700 (PDT) Date: Sun, 29 Oct 2023 07:52:39 +0000 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.42.0.820.g83a721a137-goog Message-ID: <20231029075244.2612089-1-lixiaoyan@google.com> Subject: [PATCH v5 net-next 0/5] Analyze and Reorganize core Networking Structs to optimize cacheline consumption From: Coco Li To: Jakub Kicinski , Eric Dumazet , Neal Cardwell , Mubashir Adnan Qureshi , Paolo Abeni , Andrew Lunn , Jonathan Corbet , David Ahern , Daniel Borkmann Cc: netdev@vger.kernel.org, Chao Wu , Wei Wang , Pradeep Nemavat , Coco Li Content-Type: text/plain; charset="UTF-8" Currently, variable-heavy structs in the networking stack is organized chronologically, logically and sometimes by cacheline access. This patch series attempts to reorganize the core networking stack variables to minimize cacheline consumption during the phase of data transfer. Specifically, we looked at the TCP/IP stack and the fast path definition in TCP. For documentation purposes, we also added new files for each core data structure we considered, although not all ended up being modified due to the amount of existing cacheline they span in the fast path. In the documentation, we recorded all variables we identified on the fast path and the reasons. We also hope that in the future when variables are added/modified, the document can be referred to and updated accordingly to reflect the latest variable organization. Tested: Our tests were run with neper tcp_rr using tcp traffic. The tests have $cpu number of threads and variable number of flows (see below). Tests were run on 6.5-rc1 Efficiency is computed as cpu seconds / throughput (one tcp_rr round trip). The following result shows efficiency delta before and after the patch series is applied. On AMD platforms with 100Gb/s NIC and 256Mb L3 cache: IPv4 Flows with patches clean kernel Percent reduction 30k 0.0001736538065 0.0002741191042 -36.65% 20k 0.0001583661752 0.0002712559158 -41.62% 10k 0.0001639148817 0.0002951800751 -44.47% 5k 0.0001859683866 0.0003320642536 -44.00% 1k 0.0002035190546 0.0003152056382 -35.43% IPv6 Flows with patches clean kernel Percent reduction 30k 0.000202535503 0.0003275329163 -38.16% 20k 0.0002020654777 0.0003411304786 -40.77% 10k 0.0002122427035 0.0003803674705 -44.20% 5k 0.0002348776729 0.0004030403953 -41.72% 1k 0.0002237384583 0.0002813646157 -20.48% On Intel platforms with 200Gb/s NIC and 105Mb L3 cache: IPv6 Flows with patches clean kernel Percent reduction 30k 0.0006296537873 0.0006370427753 -1.16% 20k 0.0003451029365 0.0003628016076 -4.88% 10k 0.0003187646958 0.0003346835645 -4.76% 5k 0.0002954676348 0.000311807592 -5.24% 1k 0.0001909169342 0.0001848069709 3.31% v5 changes: 1) removed snmp patch changes for next net-dev cycle. Pending work: move file out of uapi. 2) updated cache group size requirements. Chosen to not use cachelines but actual sum of struct member sizes to not make assumptions on cacheline sizes. Coco Li (5): Documentations: Analyze heavily used Networking related structs cache: enforce cache groups netns-ipv4: reorganize netns_ipv4 fast path variables net-device: reorganize net_device fast path variables tcp: reorganize tcp_sock fast path variables Documentation/networking/index.rst | 1 + .../networking/net_cachelines/index.rst | 13 + .../net_cachelines/inet_connection_sock.rst | 47 ++++ .../networking/net_cachelines/inet_sock.rst | 41 +++ .../networking/net_cachelines/net_device.rst | 175 ++++++++++++ .../net_cachelines/netns_ipv4_sysctl.rst | 155 +++++++++++ .../networking/net_cachelines/snmp.rst | 132 ++++++++++ .../networking/net_cachelines/tcp_sock.rst | 154 +++++++++++ include/linux/cache.h | 25 ++ include/linux/netdevice.h | 117 +++++---- include/linux/tcp.h | 248 ++++++++++-------- include/net/netns/ipv4.h | 47 ++-- net/core/dev.c | 56 ++++ net/core/net_namespace.c | 43 +++ net/ipv4/tcp.c | 93 +++++++ 15 files changed, 1165 insertions(+), 182 deletions(-) create mode 100644 Documentation/networking/net_cachelines/index.rst create mode 100644 Documentation/networking/net_cachelines/inet_connection_sock.rst create mode 100644 Documentation/networking/net_cachelines/inet_sock.rst create mode 100644 Documentation/networking/net_cachelines/net_device.rst create mode 100644 Documentation/networking/net_cachelines/netns_ipv4_sysctl.rst create mode 100644 Documentation/networking/net_cachelines/snmp.rst create mode 100644 Documentation/networking/net_cachelines/tcp_sock.rst -- 2.42.0.820.g83a721a137-goog