Received: by 2002:ab2:6857:0:b0:1ef:ffd0:ce49 with SMTP id l23csp2708749lqp; Mon, 25 Mar 2024 07:14:03 -0700 (PDT) X-Forwarded-Encrypted: i=3; AJvYcCX5JFOvrjD8Gh4ehUHFHnLGtf/wtmjCUmCnik6QQ1fcOQWd4yEypHBMniTU+dH9PvwHtj99sjG6S+l0hiW18E0ZY7ROjTdXPjy3cxjceA== X-Google-Smtp-Source: AGHT+IEg9WUN6WsPquBLsfNCOpw1eLHcvcfRo7UMcb/ScWLjVP4zKDMa6WCjuK2LxBREAFESX3JF X-Received: by 2002:a92:db41:0:b0:366:9868:4c5e with SMTP id w1-20020a92db41000000b0036698684c5emr8847020ilq.10.1711376043407; Mon, 25 Mar 2024 07:14:03 -0700 (PDT) ARC-Seal: i=2; a=rsa-sha256; t=1711376043; cv=pass; d=google.com; s=arc-20160816; b=oucBaDygJQdHgY+Wy04+u00bJECFdCmqx/L2gLW6Ecp+b9YGX6ACC45wAkjvMru64c rqLLe4gC0TbjujPhJeFz+M1SDaYctJQQsU/Uv3uk/SNrLGHTsC/Xe3RvhN4532oZddo/ gy359LKuZoFgAtHQ8mCErgWKBFDvNjnSvLxKbL++ozcv76ljBARej/R500ZK6l7LvqCZ vsFziN5uDUB3J9AUA/M9a4X+GZAOJaGZ6hQVKhPs42oXYvQr+zIHFyvd4mCvteXBJ9dB q8YuyWjLWU2sZdSVIDGSQagzxmRoc7crok5VR44E8et/kXqwUNzJzL4Jj7NbLkdUz8v1 7SOA== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=in-reply-to:content-disposition:mime-version:list-unsubscribe :list-subscribe:list-id:precedence:references:message-id:subject:cc :to:from:date:sender:dkim-signature; bh=yoLFByqv9SuKcb48SqGjXzMZ/gFLFOWm84zGVd1qysA=; fh=HjNI7Wb20G88+Hl9sR2IEbGOYrJqKVnmdld0IyafzJ4=; b=T/8+3Dj3jiwqcPFU6H6KLw5jcAyY6b6bTjMg28WQiHvNfTe+pWekZ//Sgn3SkRPvnR JwPHejie1cteNGPN0suCHE/bZu6ts4CGThgaWlQBLDGlwJIjalxx2/L1sBUsJi5EKotV C5A7WFXXP9M5ui6uyqObF/vvPqMGSd1n/HR8lVvs67PBZGCnYZoyw/7n82yg53pOOGmj YgtRZXOM5MkNDHN0+/exMwulBvo6iY6WQaCZnlDhN3fWewswGKi+X7cRaWptUsMhuVfL EL0gVLmDFiFkyC4LSXZqwOIN4H4V8PxMCgzM3wVf2TrXztJfWbr+nEg+16lhUQVq9mtM FkUQ==; dara=google.com ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@gmail.com header.s=20230601 header.b=lRgqPuxZ; arc=pass (i=1 spf=pass spfdomain=gmail.com dkim=pass dkdomain=gmail.com); spf=pass (google.com: domain of linux-kernel+bounces-116846-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-116846-linux.lists.archive=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from sv.mirrors.kernel.org (sv.mirrors.kernel.org. [2604:1380:45e3:2400::1]) by mx.google.com with ESMTPS id s12-20020a63770c000000b005dc6e684fd7si7443253pgc.451.2024.03.25.07.14.03 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 25 Mar 2024 07:14:03 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel+bounces-116846-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20230601 header.b=lRgqPuxZ; arc=pass (i=1 spf=pass spfdomain=gmail.com dkim=pass dkdomain=gmail.com); spf=pass (google.com: domain of linux-kernel+bounces-116846-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-116846-linux.lists.archive=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sv.mirrors.kernel.org (Postfix) with ESMTPS id 324FC2E0263 for ; Mon, 25 Mar 2024 14:12:01 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id ED49B1BAC20; Mon, 25 Mar 2024 11:13:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="lRgqPuxZ" Received: from mail-ej1-f48.google.com (mail-ej1-f48.google.com [209.85.218.48]) (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 8EE6F13B58D for ; Mon, 25 Mar 2024 10:36:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.48 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711363003; cv=none; b=HUOOxJpSvfGLtNDFcuThXAGVI+JdcjlG7ePf5zmiYghLtcJ1wHa0RWd2Qw0TxAl9maNVTTwWK96r8s1UNyzaaK5ZoKIcXiAh/CNNu18oDzP+9w2lgbwbIRrxTCqmVtzASB4nfKCf7MLC8u9o86UHT6wwjMDu+0bcy1kHug0znL8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711363003; c=relaxed/simple; bh=YdAGvLHgaCqu4Jw0vs2raNroBxAXX1REtXxAcoS0g+A=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cPgxxaHYBx0pIL+OZUXp19cjYb+EXmNm2GTACJa1zntsT6JTEH0s54H8Z5rJXcSC8m1OgTVsw4j3gVtM85Ws7y3/wMQ18vD8KUMnFHQ1msqcJ5kFVc/nmD16ZJoUBWjPqYRh0qfdL794En/3060+5lCzTzcQQwX67EE9vWfOFDA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=lRgqPuxZ; arc=none smtp.client-ip=209.85.218.48 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-ej1-f48.google.com with SMTP id a640c23a62f3a-a4a34516955so101964166b.0 for ; Mon, 25 Mar 2024 03:36:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1711363000; x=1711967800; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=yoLFByqv9SuKcb48SqGjXzMZ/gFLFOWm84zGVd1qysA=; b=lRgqPuxZZAM08nUApBbz4DYLHqBcSAzSd7iCjg2hoixB09E7MyXwfv+W4w84gWKpZN oDZ+KAbKrRxQX69nmj9lxKZ3zNtRqSMqJqCUMuF4+/w28VCLu0dBafBnDXEQ6EzDjyZD XN7NgFEP7doiEWo9Hi+Imngq2RUevZNbi16K++arq2ajF5DqRq+Xtzpgk6xG4BED57p7 aed3Nd1LPJnp02cxda/HBqf9HT6NzbeuGny1NBytQtFASuW5PM/aJH5b7V70AHw9r8vY yE8cjNPyxidGsSBIc072IOpmhuxQLIJxRjCzbuq4J0ot71Y0Fga0BBsq1DXPcXGKcuW+ pr8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1711363000; x=1711967800; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=yoLFByqv9SuKcb48SqGjXzMZ/gFLFOWm84zGVd1qysA=; b=vxm997gIP2YEYsX9fL9TYwnGPvaffzB3IxhzbYWRoYWCcqrpql8td12U3GENhMUVyL lkaK710mY7aMJtMe/DsXeoWQ85FeGh6nAfZF6gnjwPxYK5PqGYNHa3grrhZxyO44M65u g2GpMAFTufUYfNeEjZ0jTzemhpBFbWASTADSjzrb1yVWcP70otSN4Yac/DLa+SFXLLdx qqGBbuBISrgMnjK3Z3weRyZ4I0/PVKN4m4lZ/90KDxh3bD1nbrtj4IM5uszNiZ6S/qOM Q2bRMipD5iJUBwArKpXiIdjLXmH0lgcJiBiyFC/tK8Zs39706zvEqvr+sSulbN8tZ9LT 65JQ== X-Forwarded-Encrypted: i=1; AJvYcCVj83+kKpOy0nbpDoIrdWRbG8fYXZqNR+M45CeRYnS9/DL0KrkCZdVViBny8ggoWXUZSh7yBON2pc9N5QPWJoGfkvk7/dCFCIPHae0B X-Gm-Message-State: AOJu0Yz2QpW4Q4Bt4oosAtCALEBzRFmxNk3rHfpJ4eja5IC7fWIwruxz IeZ0Oqlr5gyTxMFeJP/MQnOzgbNryfBbIHpd/cmDxGSzbrlFbXtP X-Received: by 2002:a17:906:fc0d:b0:a46:4d16:439b with SMTP id ov13-20020a170906fc0d00b00a464d16439bmr4344370ejb.43.1711362999349; Mon, 25 Mar 2024 03:36:39 -0700 (PDT) Received: from gmail.com (1F2EF63C.nat.pool.telekom.hu. [31.46.246.60]) by smtp.gmail.com with ESMTPSA id p2-20020a1709060e8200b00a46cddf1efbsm2927821ejf.29.2024.03.25.03.36.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 25 Mar 2024 03:36:38 -0700 (PDT) Sender: Ingo Molnar Date: Mon, 25 Mar 2024 11:36:36 +0100 From: Ingo Molnar To: Shrikanth Hegde Cc: peterz@infradead.org, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, qyousef@layalina.io, linux-kernel@vger.kernel.org, vschneid@redhat.com Subject: Re: [PATCH v3 0/2] sched: Minor changes for rd->overload access Message-ID: References: <20240325054505.201995-1-sshegde@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240325054505.201995-1-sshegde@linux.ibm.com> * Shrikanth Hegde wrote: > v2 -> v3: > - Wrapped check for value change inside ser_rd_overload_status > as suggested by Qais. > - Added reviewed-by tags. > > v1 -> v2: > - dropped Fixes tag. > - Added one of the perf probes in the changelog for reference. > - Added reviewed-by tags. > > tl;dr > When running workloads in large systems, it was observed that access to > rd->overload was taking time. It would be better to check the value > before updating since value changes less often. Patch 1/2 does that. > With patch updates happen only if necessary. CPU Bus traffic reduced a > bit. No significant gains in workload performance. Could you please post this against the latest scheduler tree, ie. tip:sched/core? Thanks, Ingo