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=-2.4 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, URIBL_BLOCKED,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 63DF2C43142 for ; Tue, 31 Jul 2018 15:04:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1B07D20870 for ; Tue, 31 Jul 2018 15:04:54 +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="eoU7DyD/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1B07D20870 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 S1732503AbeGaQpg (ORCPT ); Tue, 31 Jul 2018 12:45:36 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:35906 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732302AbeGaQpg (ORCPT ); Tue, 31 Jul 2018 12:45:36 -0400 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=+cMdTyIUVDzKVmgmL9p6STfx6PrfnxOtk/KHQV6RXrs=; b=eoU7DyD/HVjH82aESm5LIahaw krIFJkBf5X1zx4X91YAjtNJMj78MvElQIaiXv9YSqZanrP6ZL0zX2VgkWw7kLuwSv3ykg9hkXJVuF fnVc5MvIxfk31X6giXH84MVIwOgUHF5bulmOjMt75Y8XcE0ZSzr0FvjwIi7gPCVSUB+eJ01ipzADL XsnLQgI7UxckE/8CXg6Dk5cQGCXYXaw1LMRu2OB9ks5RixfKrKRd0HiQmNnpOxDCC6k2UTvwYZsyX bBWZb0F7CRMDf10hTWz1kPjEIUu4dsnayWL+KDQofberpMNUX0D40CCpvKQ/KUfydLzyy/d2aU9iM yngi3zK6w==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fkWCW-0001o0-Iy; Tue, 31 Jul 2018 15:04:40 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id CA41720532353; Tue, 31 Jul 2018 17:04:38 +0200 (CEST) Date: Tue, 31 Jul 2018 17:04:38 +0200 From: Peter Zijlstra To: Srinivas Pandruvada Cc: Eero Tamminen , Mel Gorman , Francisco Jerez , lenb@kernel.org, rjw@rjwysocki.net, ggherdovich@suse.cz, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, juri.lelli@redhat.com, viresh.kumar@linaro.org, Chris Wilson , Tvrtko Ursulin , Joonas Lahtinen Subject: Re: [PATCH 4/4] cpufreq: intel_pstate: enable boost for Skylake Xeon Message-ID: <20180731150438.GE2458@hirez.programming.kicks-ass.net> References: <20180605214242.62156-1-srinivas.pandruvada@linux.intel.com> <20180605214242.62156-5-srinivas.pandruvada@linux.intel.com> <87bmarhqk4.fsf@riseup.net> <20180728123639.7ckv3ljnei3urn6m@techsingularity.net> <605cfcb3f315917c5970f452fab988ae1dc946ff.camel@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <605cfcb3f315917c5970f452fab988ae1dc946ff.camel@linux.intel.com> 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 Mon, Jul 30, 2018 at 07:06:21AM -0700, Srinivas Pandruvada wrote: > On Mon, 2018-07-30 at 14:16 +0300, Eero Tamminen wrote: > > Questions: > > > > * Does currently kernel CPU freq management have any idea which IO > > devices share TDP with the CPU cores? > No. The requests we do to hardware is just indication only (HW can > ignore it). The HW has a bias register to adjust and distribute power > among users. > We can have several other active device on servers beside CPU which > when runs need extra power. So the HW arbitrates power. That's not entirely accurate AFAIK. "No" is accurate for Intel, but the ARM people have their IPA thing (not a beer): https://developer.arm.com/open-source/intelligent-power-allocation drivers/thermal/power_allocator.c which IIUC interacts with their cpufreq driver to disallow certain OPP states. And note that I discourage intel_pstate active mode.