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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 B0E5EC433E0 for ; Thu, 28 May 2020 19:08:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C51E206A1 for ; Thu, 28 May 2020 19:08:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406218AbgE1TIh (ORCPT ); Thu, 28 May 2020 15:08:37 -0400 Received: from mail-ej1-f67.google.com ([209.85.218.67]:44029 "EHLO mail-ej1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406081AbgE1TId (ORCPT ); Thu, 28 May 2020 15:08:33 -0400 Received: by mail-ej1-f67.google.com with SMTP id a2so1108946ejb.10; Thu, 28 May 2020 12:08:33 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:references:user-agent:from:to:cc:subject :in-reply-to:message-id:date:mime-version; bh=A3AB3XwTTYzt1zONUlGDw1t5RFjEaflenV4Wqzl2A4A=; b=gPbV4Hx/5UZ7SPPS8e8R1QNd+d1fPglmN4O+z0VaSDvGSE1/l7B9hrCXrrMlEF6vab EazsmY6iRVVWdDogBnBhasX8moWX6PhVetpjHmoSVjbGhnoskmlm28b9YHH2l9A5g5j4 9UJBLWBPDRKOfX4RFxV+XeTm4THSO+L/YH1k1j0H4i7XmacjGd4vzKGepURymiy+ceIa 6Rnj8zYXWGVYnBsZr6dPonYm1D+lf4VR56VUjR5mQjQO5r7ASs2Z79LLHSI+xPbSS+b/ cvJMxoXzROpqWWyPO+nBodgAs3INjqDdWvS9VE1M4IgelNV6oIZl+Qq7TimRvtXE6m+A UFAw== X-Gm-Message-State: AOAM531spj+Jx2Vi4qdqvpqbuGZYcM5EM4msc/Bfg0LEbN9k3YJT0NDr ByHDQgjwTKLq05voLxgnYl6YaleKN7w= X-Google-Smtp-Source: ABdhPJxHprawmsGEdEbW5FMlvuq5wQanGA4PqoeRbJBN6xHhW/L2Fvt/XHMK8cJRmwE1KMis7HFL1g== X-Received: by 2002:a17:906:7d90:: with SMTP id v16mr4270015ejo.554.1590692911706; Thu, 28 May 2020 12:08:31 -0700 (PDT) Received: from darkstar ([51.154.17.58]) by smtp.gmail.com with ESMTPSA id j31sm1208387edb.12.2020.05.28.12.08.29 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Thu, 28 May 2020 12:08:30 -0700 (PDT) References: <20200511154053.7822-1-qais.yousef@arm.com> <20200528132327.GB706460@hirez.programming.kicks-ass.net> <20200528155800.yjrmx3hj72xreryh@e107158-lin.cambridge.arm.com> <20200528161112.GI2483@worktop.programming.kicks-ass.net> <20200528165130.m5unoewcncuvxynn@e107158-lin.cambridge.arm.com> <20200528182913.GQ2483@worktop.programming.kicks-ass.net> User-agent: mu4e 1.4.3; emacs 26.3 From: Patrick Bellasi To: Peter Zijlstra Cc: Qais Yousef , Giovanni Gherdovich , Ingo Molnar , Randy Dunlap , Jonathan Corbet , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Luis Chamberlain , Kees Cook , Iurii Zaikin , Quentin Perret , Valentin Schneider , Pavan Kondeti , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 1/2] sched/uclamp: Add a new sysctl to control RT default boost value In-reply-to: <20200528182913.GQ2483@worktop.programming.kicks-ass.net> Message-ID: <878shb3mj6.derkling@matbug.net> Date: Thu, 28 May 2020 21:08:29 +0200 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [+Giovanni] On Thu, May 28, 2020 at 20:29:14 +0200, Peter Zijlstra wrote... > On Thu, May 28, 2020 at 05:51:31PM +0100, Qais Yousef wrote: >> I had a humble try to catch the overhead but wasn't successful. The observation >> wasn't missed by us too then. > > Right, I remember us doing benchmarks when we introduced all this and > clearly we missed something. I would be good if Mel can share which > benchmark hurt most so we can go have a look. Indeed, would be great to have a description of their test setup and results. Perhaps Giovanni can also support us on that.