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=-2.1 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT autolearn=ham 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 64D5FC433F4 for ; Wed, 29 Aug 2018 12:45:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1888220867 for ; Wed, 29 Aug 2018 12:45:13 +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="2PW0vxDh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1888220867 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728659AbeH2Ql4 (ORCPT ); Wed, 29 Aug 2018 12:41:56 -0400 Received: from merlin.infradead.org ([205.233.59.134]:52818 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727452AbeH2Ql4 (ORCPT ); Wed, 29 Aug 2018 12:41:56 -0400 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=COjqZmReYv6wVg8dlSBcrb0SxfyyNTJlBQxG6+ian+0=; b=2PW0vxDhyL9CyQwcUwGZELHcg 9Z5aoLxU/bKq2fhY7EEqJrG0D8zfs+sW2fveQsjduPrivDXG0sB0Lx4sfPAUaNk8t7WWfHNTPvu2p MCf24gcsS8hU1xzuW+sV4cIBIUkZaDnmGJwis3Is1CTN3a8GQ1Rz4T91qk9L4qCzjOcP00wbycV/J 3yq/NU7gLkbBzRFkbVeAYALhiisxABE6C30kVC2qnDnh2E0Ay2yX7yPYuqrTY8/zrM72clxdFuU0i 3HbWZtvmxIxeF1fvxtN3Y275Sf3rg8FrGQxtAFqXUUYMNqtzF4VlTr5JNLUs0mDY3cpu6TjrLEHEw Phz9iKpsA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fuzqM-00014l-Oz; Wed, 29 Aug 2018 12:45:07 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 48C052059B9FD; Wed, 29 Aug 2018 14:45:03 +0200 (CEST) Date: Wed, 29 Aug 2018 14:45:03 +0200 From: Peter Zijlstra To: Vincent Guittot Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, kernellwp@gmail.com Subject: Re: [PATCH] sched/schedutil : optimize utilization scaling for guest kernel Message-ID: <20180829124503.GU24124@hirez.programming.kicks-ass.net> References: <1535532702-3508-1-git-send-email-vincent.guittot@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1535532702-3508-1-git-send-email-vincent.guittot@linaro.org> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 29, 2018 at 10:51:42AM +0200, Vincent Guittot wrote: > Scaling the utilization of CPUs with irq util_avg in schedutil doesn't give > any benefit and just waste CPU cycles when irq time is not accounted but > only steal time. > Add an internal _scale_irq_capacity() for scale_rt_capacity but scale > cpu utilization in schedutil only if we are accounting irq time. This makes a mess of things; also it doesn't really do what it says. Even if we have CONFIG_IRQ_TIME_ACCOUNTING, that doesn't mean we do it, just that it is capable.