From mboxrd@z Thu Jan 1 00:00:00 1970 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 6D287E92711 for ; Thu, 5 Oct 2023 15:43:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233418AbjJEPnn (ORCPT ); Thu, 5 Oct 2023 11:43:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233313AbjJEPnN (ORCPT ); Thu, 5 Oct 2023 11:43:13 -0400 Received: from smtp-fw-80007.amazon.com (smtp-fw-80007.amazon.com [99.78.197.218]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 97CAE6702 for ; Thu, 5 Oct 2023 07:59:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1696517979; x=1728053979; h=message-id:date:mime-version:to:cc:from:subject: content-transfer-encoding; bh=F4DXyzvks4SjCO39rTIRcQaJk8nbyPccC5eJCgdjSQs=; b=p8ju+BljMo5mjb0Dnophgy8dJZkzo02Z6cbVHRRhulo3X2bkVPA/tjSz 16jb/xPNTgOKl/p0idI5ALfD1hdMDWXz6P07UDbKE6XAun7rLwOqVzshi B1mvqiHYhdxy3yxgXkjEnvQFDZ8jGleW7UDeXyoTkogAXc7Bn/xhpkjXW k=; X-IronPort-AV: E=Sophos;i="6.03,203,1694736000"; d="scan'208";a="243635462" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-iad-1a-m6i4x-54a853e6.us-east-1.amazon.com) ([10.25.36.210]) by smtp-border-fw-80007.pdx80.corp.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Oct 2023 14:59:36 +0000 Received: from smtpout.prod.us-east-1.prod.farcaster.email.amazon.dev (iad7-ws-svc-p70-lb3-vlan3.iad.amazon.com [10.32.235.38]) by email-inbound-relay-iad-1a-m6i4x-54a853e6.us-east-1.amazon.com (Postfix) with ESMTPS id 9C63A484A9; Thu, 5 Oct 2023 14:59:33 +0000 (UTC) Received: from EX19MTAUEB001.ant.amazon.com [10.0.29.78:19359] by smtpin.naws.us-east-1.prod.farcaster.email.amazon.dev [10.0.50.19:2525] with esmtp (Farcaster) id ea6e9579-e480-4773-b428-3ff4a08893c4; Thu, 5 Oct 2023 14:59:33 +0000 (UTC) X-Farcaster-Flow-ID: ea6e9579-e480-4773-b428-3ff4a08893c4 Received: from EX19D028UEC003.ant.amazon.com (10.252.137.159) by EX19MTAUEB001.ant.amazon.com (10.252.135.108) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.37; Thu, 5 Oct 2023 14:59:32 +0000 Received: from [10.136.71.253] (10.136.71.253) by EX19D028UEC003.ant.amazon.com (10.252.137.159) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.37; Thu, 5 Oct 2023 14:59:31 +0000 Message-ID: <010edf5a-453d-4c98-9c07-12e75d3f983c@amazon.com> Date: Thu, 5 Oct 2023 10:59:28 -0400 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US To: "stable@vger.kernel.org" , , CC: Greg KH , , From: Luiz Capitulino Subject: [5.15,6.1] Please apply a89c6bcdac22bec1bfbe6e64060b4cf5838d4f47 Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.136.71.253] X-ClientProxiedBy: EX19D042UWB003.ant.amazon.com (10.13.139.135) To EX19D028UEC003.ant.amazon.com (10.252.137.159) Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Hi, We found that commits 46bdb4277f98 and 0388f9c74330 (merged in v5.12) introduced more than 40% performance regression in UnixBench's process creation benchmark when comparing 5.10 with 5.15 and 6.1 on AWS' virtualized Graviton instances. This has been mostly fixed by the following upstream commit: """ commit a89c6bcdac22bec1bfbe6e64060b4cf5838d4f47 Author: Gabriel Krisman Bertazi Date: Mon Jan 9 12:19:55 2023 -0300 arm64: Avoid repeated AA64MMFR1_EL1 register read on pagefault path """ (This is merged in v6.3 and applies cleanly in 5.15 and 6.1). We performed functional and performance regression tests on both 5.15 and 6.1 with this patch applied. We can also observe 10% improvement in system time in other benchmarks. Just to be transparent, we initially observed 5% degradation in a benchmark we have with fio randwrite on EBS volumes with our 6.1 downstream kernel but this doesn't seem reproducible and we don't think this patch would cause it. Here's some quick UnixBench process creation measurements on m7gd.16xlarge instance type. All results are the average of 5 consecutive runs with a single process: * 5.10.197: 9886.68 lps (baseline) * 6.1.55: 5531.24 lps (unfixed - 44% degradation) * 5.15.133: 5960.12 lps (unfixed - 39% degradation) * 5.15.133: 10306.4 lps (fixed - actually better than baseline) * 6.1.55: 9393.42 lps (fixed - degradation reduced to 5%) - Luiz