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, 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 CB8BAC4360C for ; Wed, 16 Oct 2019 08:14:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A09232064B for ; Wed, 16 Oct 2019 08:14:16 +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="gyFxNMYF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391481AbfJPIOP (ORCPT ); Wed, 16 Oct 2019 04:14:15 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:38998 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727050AbfJPIOO (ORCPT ); Wed, 16 Oct 2019 04:14:14 -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=muEAjSBNXIfkLN3HPiA3QlifKtY10OMjDOU7+2ucKH8=; b=gyFxNMYFYwJPyO/2uMQ6dizoB S28YnsW1It2VmkLf44hVQLxRI5ObiW8L2hn8JInaLX2CvR8nn3iPCtVFSvego3/PmilrqCe/RsCvL jkY3c8SeoosMUNTGOuU8PvEMEhgVtNGaOfJiTBbTnuBG8/vpgrjxaeXO80G+FuPaTDdwRSICY3bw3 9HEnfMAKlRPD1ch7EYTntBBAsNRMU431NMCdzTaNxii5uQnqcBxj2D9nMLw1+CRl43xLdzAC/ZpZn I2NZmdLpWkOCXuYaqbmcYGawIs49on0amO7efAKINbII6pBJ4jWGVbXrq8h4JYXW9ym25Wi7EwUT1 MvOktnzFw==; 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 1iKeRb-0003dT-3K; Wed, 16 Oct 2019 08:14:07 +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 368F53032F8; Wed, 16 Oct 2019 10:13:10 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 0C50C20B972E4; Wed, 16 Oct 2019 10:14:05 +0200 (CEST) Date: Wed, 16 Oct 2019 10:14:05 +0200 From: Peter Zijlstra To: Srinivas Pandruvada Cc: tony.luck@intel.com, bp@alien8.de, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, bberg@redhat.com, x86@kernel.org, linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org, hdegoede@redhat.com, ckellner@redhat.com Subject: Re: [PATCH 1/2] x86, mce, therm_throt: Optimize logging of thermal throttle messages Message-ID: <20191016081405.GO2328@hirez.programming.kicks-ass.net> References: <2c2b65c23be3064504566c5f621c1f37bf7e7326.camel@redhat.com> <20191014212101.25719-1-srinivas.pandruvada@linux.intel.com> <20191015084833.GD2311@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-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 15, 2019 at 06:31:46AM -0700, Srinivas Pandruvada wrote: > On Tue, 2019-10-15 at 10:48 +0200, Peter Zijlstra wrote: > > On Mon, Oct 14, 2019 at 02:21:00PM -0700, Srinivas Pandruvada wrote: > > > Some modern systems have very tight thermal tolerances. Because of > > > this > > > they may cross thermal thresholds when running normal workloads > > > (even > > > during boot). The CPU hardware will react by limiting > > > power/frequency > > > and using duty cycles to bring the temperature back into normal > > > range. > > > > > > Thus users may see a "critical" message about the "temperature > > > above > > > threshold" which is soon followed by "temperature/speed normal". > > > These > > > messages are rate limited, but still may repeat every few minutes. > > > > > > The solution here is to set a timeout when the temperature first > > > exceeds > > > the threshold. > > > > Why can we even reach critical thresholds when the fans are working? > > I > > always thought it was BAD to ever reach the critical temps and have > > the > > hardware throttle. > CPU temperature doesn't have to hit max(TjMax) to get these warnings. > OEMs has an ability to program a threshold where a thermal interrupt > can be generated. In some systems the offset is 20C+ (Read only value). > > In recent systems, there is another offset on top of it which can be > programmed by OS, once some agent can adjust power limits dynamically. > By default this is set to low by the firmware, which I guess the prime > motivation of Benjamin to submit the patch. That all sounds like the printk should be downgraded too, it is not a KERN_CRIT warning. It is more a notification that we're getting warm.