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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 BCB2FC2BBCF for ; Fri, 18 Dec 2020 15:33:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 93F0723B53 for ; Fri, 18 Dec 2020 15:33:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728016AbgLRPdn (ORCPT ); Fri, 18 Dec 2020 10:33:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41616 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725878AbgLRPdm (ORCPT ); Fri, 18 Dec 2020 10:33:42 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C74AC0617A7; Fri, 18 Dec 2020 07:33:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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; bh=Ivzl+SgN1fSmo4LHwIz5rmX0mNUDsLZaBvVQA2TlPFI=; b=L7u/5ZwMZEsfNyllfNMqlLqYso icEocTd4pIA4y+rJOlU5KquYog1RzGuDm+xrPIwzUi12t4SMvvcYbLdSxbb2e9leLcrFUss2Fl0n1 y2niBfN26cnXhCZ9uYXQ6BGCZ9/jtNplC8TR3MjoCXyF/lsWXIrAonBODAuVSzm4u8kttnbORN8A8 s78dbXKm0rZp0GBe4QkUW6h+kVWNXz8ZsG+PEi4uJS4MEaBOUPhMV8/g3izbi0pLERo4y8m8fDpeV KJhwWf5I1RmRaDDyYH6a2gJ0lgSmvvfI51r6Pvf8Oy9GX6HwdX0LLyy6VwuADyTyP+VZn1637oxDp 7aEb+Cdg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kqHkB-0001Qr-8V; Fri, 18 Dec 2020 15:32:35 +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 CADA5300B22; Fri, 18 Dec 2020 16:32:31 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id B45562BFB9808; Fri, 18 Dec 2020 16:32:31 +0100 (CET) Date: Fri, 18 Dec 2020 16:32:31 +0100 From: Peter Zijlstra To: Doug Smythies Cc: "'Rafael J. Wysocki'" , 'Giovanni Gherdovich' , "'Rafael J. Wysocki'" , 'Linux PM' , 'LKML' , 'Viresh Kumar' , 'Srinivas Pandruvada' , efault@gmx.de, Mel Gorman , Vincent Guittot , Ingo Molnar , Thomas Gleixner , Juri Lelli Subject: Re: [PATCH v1 0/4] cpufreq: Allow drivers to receive more information from the governor Message-ID: <20201218153231.GB2414@hirez.programming.kicks-ass.net> References: <20360841.iInq7taT2Z@kreacher> <1607445035.2673.64.camel@suse.com> <001d01d6cd96$601c8a80$20559f80$@net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <001d01d6cd96$601c8a80$20559f80$@net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 08, 2020 at 11:14:36AM -0800, Doug Smythies wrote: > At least on my system, it is most evident for some of the pipe type tests, > where the schedutil governor has never really known what to do. This patch > set seems to add enough of a downward bias that this version of the schedutil > governor now behaves much like the other versions Yeah, pipe relies on task-task interaction, where one task waits on another, and by boosting the producer the consumer can start earlier and we get more cycles done etc.. Rather similar to IO-wait, where by boosting the producer we gain throughput. schedutil doesn't track anything useful here, but it is a semi common pattern and it would be really good if we could somehow fix this. We obviously have access to the task A wakes task B information, but I'm not sure what to do with it, we're tried some things like this in the past (although for slightly different reasons) and they've always ended up being a mess :/