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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id BF488CD3420 for ; Tue, 3 Sep 2024 12:22:07 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 451636B0251; Tue, 3 Sep 2024 08:22:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 400976B0252; Tue, 3 Sep 2024 08:22:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2C8728D015F; Tue, 3 Sep 2024 08:22:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 0EDDB6B0251 for ; Tue, 3 Sep 2024 08:22:07 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id AF5111A016A for ; Tue, 3 Sep 2024 12:22:06 +0000 (UTC) X-FDA: 82523339052.19.3477106 Received: from mail-qv1-f54.google.com (mail-qv1-f54.google.com [209.85.219.54]) by imf03.hostedemail.com (Postfix) with ESMTP id F0C0F20006 for ; Tue, 3 Sep 2024 12:22:04 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=linaro.org header.s=google header.b=hYeWvi7O; spf=pass (imf03.hostedemail.com: domain of anders.roxell@linaro.org designates 209.85.219.54 as permitted sender) smtp.mailfrom=anders.roxell@linaro.org; dmarc=pass (policy=none) header.from=linaro.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1725366030; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding:in-reply-to: references:dkim-signature; bh=1iNKROeTecbC7NJJEQLnhWG64uAyJxfHsOWVXv+2sIQ=; b=bZPfvpvjVfiwUPiJbklxSOGhJZONwb2wPcCzfBLFoBd4d21mSv8/e/IVn7uO2nCyZ2ahNI L8gkH78hvfi739Ka4u9fKVXPRUTYqQlUzRwIs88qUdDXwGDFZ5CZnA1ZZbn5dfiq8LBAkz ZywosQuXcc13sIKTnq66rqco0J5oc+8= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1725366030; a=rsa-sha256; cv=none; b=m6SHyvynpnqYeTGpn2DLU9nvwz/EMlmnWQizB9wj19tVL2NiivosrRmWNuU6gzHYZq6+S8 o78CtdrBzsIbqpzBShXUvGe+zNZtlUmaJ5sd158oVaHc6ho+Tb6TRf4PbGXLdS2DtwQjhg AbdnQdpt2oOnMimvKM7fPQikLk9eksE= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=linaro.org header.s=google header.b=hYeWvi7O; spf=pass (imf03.hostedemail.com: domain of anders.roxell@linaro.org designates 209.85.219.54 as permitted sender) smtp.mailfrom=anders.roxell@linaro.org; dmarc=pass (policy=none) header.from=linaro.org Received: by mail-qv1-f54.google.com with SMTP id 6a1803df08f44-6c35bea4871so828146d6.2 for ; Tue, 03 Sep 2024 05:22:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1725366124; x=1725970924; darn=kvack.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=1iNKROeTecbC7NJJEQLnhWG64uAyJxfHsOWVXv+2sIQ=; b=hYeWvi7OMTu/tgp4u+y8gOBe3u1PDKs3JW4mOfL3DryFC/MTiKJsyOks0ENM+qD50j gy98bEUqui3pleSgDSvWo9ON/69eN09JESodGgvxDhGPLoVVYwdr+agdjEZrIiFpLig8 FW1evtkWZVdTft6Yj0OeUKHRJZXNVWwmNruCcEKnHaLAsXa6ogQaO5T7BenCq6dGu8Vd yqEVyrE3iBDvn7AAV0zrFqEQpoCbrcl703DizeC2/UGAQG6MB1BBThV4BjVPXYzRGQS3 cRVBxmw+CzZiXLoouSeYdnyQ950dQMPGi0CnBlOi3wBVq/GSdt/R3sr73GjV5Er+Yzw7 Ifzw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725366124; x=1725970924; h=content-transfer-encoding:cc:to:subject:message-id:date:from :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=1iNKROeTecbC7NJJEQLnhWG64uAyJxfHsOWVXv+2sIQ=; b=SNMi5Gv24pCFzrFPBzdNE86p4mbIS6hrF1QnF8xZT2C53Utoq0UKVz9W6nBSVFWPT9 HrOXRKuU9lYXmyb9q8v5ollyyGxSpujfYEWtCfUi4mZNl0N2tOPuuosbH+iySQL9aixg 4hK6YxlplKKKywtTGQ5Ot2+X4oLR1iloG53uqi1kmQv26nD8bZ6bu084xKCRVPXo7eZr vUoOWuDnkrRJjQ8KVITQiXxRpm/02/noQzq8shU2pPmpxXCapfHlPha6xpdiKCuP9kz8 +2TRefKUar8vFijZZBvL86jRPSKooOPnKPQ0oTUONXQxVVIud09AbQY0Kxa/w1N4OYtn 4WLA== X-Forwarded-Encrypted: i=1; AJvYcCUCdt393eL6kFHyqOPpqPrmtrq3y4e1A3298dl18IdIaAIDk9MDETPvfjhCGvlwFWPVUfgdNl82vw==@kvack.org X-Gm-Message-State: AOJu0YyLEWOBUvyZNNuIAl+D8nNBP5KEzvCMSt/xdNUVl4VfzrPYR606 BGlZ+DIWutEsgtLKJNTaT9nVqLDS/SXhCHuZB7axKnI6d0TQ03vCFleOzgZcuiDVcSU62NbuZBi 3YV68g+28K18uVdmkz1AhFAkeq7Er03XGLywCaw== X-Google-Smtp-Source: AGHT+IEdISPnvRdSEUjr50GKb9NjFs+AWGhLcxRrWqnXIzc2xeEAJX9J31hXyh5Q095NVa2zLCFGLhEPYKSvu7vnZ0Q= X-Received: by 2002:a05:6214:230d:b0:6c3:6da8:8cb1 with SMTP id 6a1803df08f44-6c36da88ef1mr25683596d6.5.1725366123844; Tue, 03 Sep 2024 05:22:03 -0700 (PDT) MIME-Version: 1.0 From: Anders Roxell Date: Tue, 3 Sep 2024 14:21:52 +0200 Message-ID: Subject: Potential Regression in futex Performance from v6.9 to v6.10-rc1 and v6.11-rc4 To: David Hildenbrand Cc: Arnd Bergmann , Thomas Gleixner , Ingo Molnar , Peter Zijlstra , dvhart@infradead.org, dave@stgolabs.net, andrealmeid@igalia.com, Linux Kernel Mailing List , Linux-MM Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: F0C0F20006 X-Stat-Signature: dw7bbgr9sdnu9y1qw6cicfcn53eqa85m X-HE-Tag: 1725366124-287041 X-HE-Meta: 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 wgphTlOp lvpSLJCuEeEDOtXS1xjKhNrKIPwlx/vXYAFhjvffRuASOInC/TBR3wSSjsIs86DRw9tuAvPmEWhr7V0yP8u/YzKYXAIc3HseIOONsFTseIzvHaU/Xn3kmk4dSSgTwcod+NVA8Zn98kmO3f2AO2IkaXnWaQ2eAFHrfv1Pe X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hi, I've noticed that the futex01-thread-* tests in will-it-scale-sys-threads are running about 2% slower on v6.10-rc1 compared to v6.9, and this slowdown continues with v6.11-rc4. I am focused on identifying any performance regressions greater than 2% that occur in automated testing on arm64 HW. Using git bisect, I traced the issue to commit f002882ca369 ("mm: merge folio_is_secretmem() and folio_fast_pin_allowed() into gup_fast_folio_allowed()"). My tests were performed on m7g.large and m7g.metal instances: * The slowdown is consistent regardless of the number of threads; futex1-threads-128 performs similarly to futex1-threads-2, indicating there is no scalability issue, just a minor performance overhead. * The test doesn=E2=80=99t involve actual futex operations, just dummy wake= /wait on a variable that isn=E2=80=99t accessed by other threads, so the resul= ts might not be very significant. Given that this seems to be a minor increase in code path length rather than a scalability issue, would this be considered a genuine regression? Cheers, Anders