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, URIBL_BLOCKED,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 E1AF7C432C3 for ; Fri, 15 Nov 2019 10:41:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AB9232072A for ; Fri, 15 Nov 2019 10:41:51 +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="k4Yd09/F" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727065AbfKOKlv (ORCPT ); Fri, 15 Nov 2019 05:41:51 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:37706 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727022AbfKOKlu (ORCPT ); Fri, 15 Nov 2019 05:41:50 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=IAccDbabd4kdJ+HEadLyepvJYR0lE95gi46SLtYmJXY=; b=k4Yd09/FaWg5kduhn1xEgQ/0q klkhrzjZ9cxOzw9iMrEsmRV7xeFNEmkxOc9eSt2Av/UAyr4i0AB0Vbsxf6+4NrwSIuBWOWqCTRTGL 9GyGzrqNe1/JF5AfEZC7FqYHA7YBVT+m4BC39418EDhtZgIOpBWZdW5h3nDyPJ9qxB3mrf3Lpz5Nb Z6bVQlzFpYhYbZrLDFElJzvAi5d3qe0phAHxlgcHB7UCEtaadO5zkudpdBUTQuvFZQoD8iEgL6eyP CDINFP1BzXLUvJ5IxMW33CP7XOASSFP/kEj7ixgryJoZexsyWdH4FxSKQPCD96jsokyQcHYBsl3mo t26ncrzBA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1iVZ26-0001Se-3T; Fri, 15 Nov 2019 10:40:54 +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 24BD4303D9F; Fri, 15 Nov 2019 11:39:44 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 388892B0BC1FC; Fri, 15 Nov 2019 11:40:52 +0100 (CET) Date: Fri, 15 Nov 2019 11:40:52 +0100 From: Peter Zijlstra To: "Rafael J. Wysocki" Cc: Vincent Guittot , Linux Kernel Mailing List , Ingo Molnar , Dietmar Eggemann , Juri Lelli , Steven Rostedt , Mel Gorman , Doug Smythies , Linux PM , Linus Torvalds , Thomas Gleixner , Sargun Dhillon , Tejun Heo , Xie XiuQi , xiezhipeng1@huawei.com, Srinivas Pandruvada Subject: Re: [PATCH v4] sched/freq: move call to cpufreq_update_util Message-ID: <20191115104052.GF4131@hirez.programming.kicks-ass.net> References: <1573751251-3505-1-git-send-email-vincent.guittot@linaro.org> <20191115095447.GU4114@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Fri, Nov 15, 2019 at 11:03:20AM +0100, Rafael J. Wysocki wrote: > On Fri, Nov 15, 2019 at 10:55 AM Peter Zijlstra wrote: > > So why are we making the scheduler code more ugly instead of fixing that > > driver? > > I guess we could "fix" the driver by making it rate limit MSR writes > only, but I'm not sure if that would help. So it is not clear to me what exactly intel_pstate needs and why. Like I wrote in my reply to Vincent just now, it can still store the last value, even if it doesn't act on it right away. And it can then act on that stored value at a later event, whatever is appropriate. I'm just saying that generating superfluous events is silly. But possibly I read the patch wrong.