From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f45.google.com (mail-pj1-f45.google.com [209.85.216.45]) (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 40C3D2D04A for ; Wed, 28 Feb 2024 08:32:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.45 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709109169; cv=none; b=f4qsjZPB6yATNzwQuPpTGaQiBRAsxARBEknex6CpzKiISvnoPk9F95gR3YuALZNuKjmmO+lGzRypr/i0/i9Gn/YMqdaPbm19I/+3RelDf9AHHWfFCi3pDWAOBIXdtrs2um1tUURFNRtkVKUFGDYU9TJ6ZN3c0epmVX5WNeU1G+o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709109169; c=relaxed/simple; bh=t40K0JM0NMfK3mCMUC77qdJh8lHBWSded2PQLMcMHuM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=T39lvtBSXvfQ/ywjsOU3BUBsUVkQBSvW8pGgVEYCtIqg9X/qETz2XsooiHc9nQilZYAAP5sYslTGsMvDb+fVdo/y+7jJ1Hw1ftGcQbFudmnBnlNWUt+B1zha+sf3ZWlXPcW7L4bPRXgngL1J+EVa+UD3z38D8cbXlUZVnjBc0gY= 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=eKnltFli; arc=none smtp.client-ip=209.85.216.45 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="eKnltFli" Received: by mail-pj1-f45.google.com with SMTP id 98e67ed59e1d1-29a6dcfdd30so3703671a91.0 for ; Wed, 28 Feb 2024 00:32:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1709109167; x=1709713967; darn=lists.linux.dev; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=t40K0JM0NMfK3mCMUC77qdJh8lHBWSded2PQLMcMHuM=; b=eKnltFlip5hNJP/HFL6qGkvAZwsZMmy7LxRCWTHt6LYswY7kIHcyf4v3r5KHm245kk XTlnE7sBEhUAEQGizKcomtV0mp/YbZLdw56D1A7hdgeZt9KQTrCW7h9Lv+WZmcC/gzMD /06fMfPDhyWbnF9KqmDLeII+DxQ82qurdrh987b1HoWw0GJzl7DB3EqgX4iPWC/EPrqQ YP4/licuVJktw+yezHJ2/rTT645txLpEdP3fur7Z7+Xb/acINq7EBjueG+1HhOBfpACA S6AxFql7ePio/QWk4uubb+7V/pxRznMI930dhFbp9uM7Gvhr3KNRFTd2FNZaQBumAB86 QLbg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709109167; x=1709713967; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=t40K0JM0NMfK3mCMUC77qdJh8lHBWSded2PQLMcMHuM=; b=UHhC6m5kSy0q+a94FyrOmjFtlCiwCx/uf1TQ32onfUDiAjXLl4cfGW+LgH8xvq3h0i zZtyx6WFQ8zXtRxgAAKaUQG7N7AcVyCyoMHT254ZB9riZF9OD/UZZZp2/csDtHEegfU7 QBFnwPOnkWJrKnePiq31S2U4ClzFf4szGElxm9wGmHAT3leYSdER3nueGsbhMBJZihxE WaxSbdYC6X+EmD8QXU21+mfeGfs2quWNaMl0v/fz3txM2yqmAQ7XGfjN8SV6pNacSwMT rm8EACPGUZh3YSp4j7xp/jRLjausg7+pc+AGWRKjYdktZWs0p0JBz3LupJluH2hhOJ+1 K0Jg== X-Forwarded-Encrypted: i=1; AJvYcCUYZSiH6Y5PK1Qc/h8tyv8qzc26nwUb+oURpu6YWx4uV0G+tRwIBCRcVIiG0NfGTRDIpDMgttCc38XNKgizXUi5dEx6laaWVUgXYn0= X-Gm-Message-State: AOJu0Yzl0nuI4CsS72Su5BcTfsowlRz8Y1zDTv/URGx3/Aa3qugd6hvQ w4GjjMcIYtAV5JD1dPLw9irTDZrIh7pm4p8q2gbBglvwS4tFWTzl X-Google-Smtp-Source: AGHT+IEPBy5Yel+v4FYYx1dJ/kW3sj9XgdN6GjR1Lqmv35o9Q62to13V/d1NNwcnNw4qpmaVH/AN5A== X-Received: by 2002:a17:90a:88c:b0:299:3f10:20ba with SMTP id v12-20020a17090a088c00b002993f1020bamr10292017pjc.27.1709109167564; Wed, 28 Feb 2024 00:32:47 -0800 (PST) Received: from archie.me ([103.124.138.155]) by smtp.gmail.com with ESMTPSA id sy12-20020a17090b2d0c00b00296f4fc7e60sm962560pjb.12.2024.02.28.00.32.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Feb 2024 00:32:47 -0800 (PST) Received: by archie.me (Postfix, from userid 1000) id D8B75187DBEB7; Wed, 28 Feb 2024 15:32:41 +0700 (WIB) Date: Wed, 28 Feb 2024 15:32:41 +0700 From: Bagas Sanjaya To: Abdul Anshad Azeez , edumazet@google.com, davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, corbet@lwn.net, dsahern@kernel.org, Linux Networking , Linux Kernel Mailing List , Linux Regressions Cc: Boon Ang , John Savanyo , Peter Jonasson , Rajender M Subject: Re: Network performance regression in Linux kernel 6.6 for small socket size test cases Message-ID: References: Precedence: bulk X-Mailing-List: regressions@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="aJ0FkAcvBcopWHIX" Content-Disposition: inline In-Reply-To: --aJ0FkAcvBcopWHIX Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable [also Cc: regressions ML] On Wed, Feb 28, 2024 at 12:13:27PM +0530, Abdul Anshad Azeez wrote: > During performance regression workload execution of the Linux > kernel we observed up to 30% performance decrease in a specific networking > workload on the 6.6 kernel compared to 6.5 (details below). The regressio= n is > reproducible in both Linux VMs running on ESXi and bare metal Linux. >=20 > Workload details: >=20 > Benchmark - Netperf TCP_STREAM > Socket buffer size - 8K > Message size - 256B > MTU - 1500B > Socket option - TCP_NODELAY > # of STREAMs - 32 > Direction - Uni-Directional Receive > Duration - 60 Seconds > NIC - Mellanox Technologies ConnectX-6 Dx EN 100G > Server Config - Intel(R) Xeon(R) Gold 6348 CPU @ 2.60GHz & 512G Memory >=20 > Bisect between 6.5 and 6.6 kernel concluded that this regression originat= ed > from the below commit: >=20 > commit - dfa2f0483360d4d6f2324405464c9f281156bd87 (tcp: get rid of > sysctl_tcp_adv_win_scale) > Author - Eric Dumazet > Link - > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit= /?id=3D > dfa2f0483360d4d6f2324405464c9f281156bd87 >=20 > Performance data for (Linux VM on ESXi): > Test case - TCP_STREAM_RECV Throughput in Gbps > (for different socket buffer sizes and with constant message size - 256B): >=20 > Socket buffer size - [LK6.5 vs LK6.6] > 8K - [8.4 vs 5.9 Gbps] > 16K - [13.4 vs 10.6 Gbps] > 32K - [19.1 vs 16.3 Gbps] > 64K - [19.6 vs 19.7 Gbps] > Autotune - [19.7 vs 19.6 Gbps] >=20 > >From the above performance data, we can infer that: > * Regression is specific to lower fixed socket buffer sizes (8K, 16K & 32= K). > * Increasing the socket buffer size gradually decreases the throughput im= pact. > * Performance is equal for higher fixed socket size (64K) and Autotune so= cket > tests. >=20 > We would like to know if there are any opportunities for optimization in > the test cases with small socket sizes. >=20 Can you verify the regression on current mainline (v6.8-rc6)? --=20 An old man doll... just what I always wanted! - Clara --aJ0FkAcvBcopWHIX Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQSSYQ6Cy7oyFNCHrUH2uYlJVVFOowUCZd7vpAAKCRD2uYlJVVFO o3FWAQDe+PbGL4LW/N1x23XLUSDEsqAGX9WqhwvPNQEir1nE3gEAqt155Cln5op5 oMAlTfo6KFQ5Sl5qdUv70rbcuu4T+gs= =88Qq -----END PGP SIGNATURE----- --aJ0FkAcvBcopWHIX--