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 X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4BE0BC43603 for ; Mon, 16 Dec 2019 14:56:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1A665206E0 for ; Mon, 16 Dec 2019 14:56:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="VnFNPKri" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728255AbfLPO4h (ORCPT ); Mon, 16 Dec 2019 09:56:37 -0500 Received: from merlin.infradead.org ([205.233.59.134]:40878 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728063AbfLPO4h (ORCPT ); Mon, 16 Dec 2019 09:56:37 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=3zBj6S7cwbWsVQLzYyhiT0zmek9MdQQXjrf7Gfxlmzw=; b=VnFNPKriAgQmCyl15gxSVX3YB x5wY88163f3vdws6jQCmIRIcoVWVIP1jmmizGcloh1h1pjbY7NDl7QkStx6Q79sXFyMiHkttJLG+D GBroGHysoJJ/uMBZcKsBrVq99ue8WOICC34fYah2Yxrc0fJfmFgbPoUuOasexBKpPI7vHkr+3rAPo Fv6Z/DnX/8Vy+cCpNlAJKFrfjGypC1gL8AB7fmgkYTy1rlb8EmNKeLCk2IyhRPDYdkwx7qh5pDovv 8dBQSKddWrGtH76Fr6pjEtSMTARixsEHrhFyw0UFhRdMvcag/rbr8KSIH9II4hBoLeQAhdvhFyqwi 78jOHqVkA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1igrnO-0008Gz-CK; Mon, 16 Dec 2019 14:56:26 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 9B39C3035D4; Mon, 16 Dec 2019 15:55:02 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id C6CC62B2A1918; Mon, 16 Dec 2019 15:56:24 +0100 (CET) Date: Mon, 16 Dec 2019 15:56:24 +0100 From: Peter Zijlstra To: Thara Gopinath Cc: mingo@redhat.com, ionela.voinescu@arm.com, vincent.guittot@linaro.org, rui.zhang@intel.com, qperret@google.com, daniel.lezcano@linaro.org, viresh.kumar@linaro.org, linux-kernel@vger.kernel.org, amit.kachhap@gmail.com, javi.merino@kernel.org, amit.kucheria@verdurent.com Subject: Re: [Patch v6 0/7] Introduce Thermal Pressure Message-ID: <20191216145624.GU2844@hirez.programming.kicks-ass.net> References: <1576123908-12105-1-git-send-email-thara.gopinath@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1576123908-12105-1-git-send-email-thara.gopinath@linaro.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 11, 2019 at 11:11:41PM -0500, Thara Gopinath wrote: > Test Results > > Hackbench: 1 group , 30000 loops, 10 runs > Result SD > (Secs) (% of mean) > No Thermal Pressure 14.03 2.69% > Thermal Pressure PELT Algo. Decay : 32 ms 13.29 0.56% > Thermal Pressure PELT Algo. Decay : 64 ms 12.57 1.56% > Thermal Pressure PELT Algo. Decay : 128 ms 12.71 1.04% > Thermal Pressure PELT Algo. Decay : 256 ms 12.29 1.42% > Thermal Pressure PELT Algo. Decay : 512 ms 12.42 1.15% > > Dhrystone Run Time : 20 threads, 3000 MLOOPS > Result SD > (Secs) (% of mean) > No Thermal Pressure 9.452 4.49% > Thermal Pressure PELT Algo. Decay : 32 ms 8.793 5.30% > Thermal Pressure PELT Algo. Decay : 64 ms 8.981 5.29% > Thermal Pressure PELT Algo. Decay : 128 ms 8.647 6.62% > Thermal Pressure PELT Algo. Decay : 256 ms 8.774 6.45% > Thermal Pressure PELT Algo. Decay : 512 ms 8.603 5.41% What is the conclusion, if any from these results? Clearly thermal pressuse seems to help, but what window? ISTR we default to 32ms, which is a wash for drystone, but sub-optimal for hackbench. Anyway, the patches look more or less acceptible, just a bunch of nits, the biggest being the fact that even if an architecture does not support this there is still the code and runtime overhead.