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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 290C9C433E1 for ; Mon, 17 Aug 2020 19:10:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DCD7A2072E for ; Mon, 17 Aug 2020 19:10:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597691450; bh=ZP78nRBu0zFa6HikHbRlcMnRoQrOzDOzp1XtjT6hGhc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=il5gu02VPoE58ChhMVoepngsyDbpqG1oU/KYfbZW4GBQd1JTTj7PTS4ZhYyUztRlm 6JXR8TaA1/RUb0kxFol+X4VXoaQZ5ljvQX/4tqw40xLMY7cIKVtQPQxbOkmPXi592B qL0j3A7bi06sCKzYMwUC7S0wV/O4wE/7LPk2X9iY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404069AbgHQTKt (ORCPT ); Mon, 17 Aug 2020 15:10:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:51272 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730753AbgHQPlg (ORCPT ); Mon, 17 Aug 2020 11:41:36 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 05C382075B; Mon, 17 Aug 2020 15:41:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597678895; bh=ZP78nRBu0zFa6HikHbRlcMnRoQrOzDOzp1XtjT6hGhc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fcoACj3KE218q7U1qc7Kf26gmoJsv+5oGQWbNxbQLR9EagWGfGhbuErCLwvUPJwxZ EwZWCXk4BTC64o7cRJTIiRNvzJM223DA+p2SrT0eUvyTKjk9H+4iT/1xVrjB0ZgQYM yU87yxjEiysgRvLrammdIX91H33AYA+wBILqGi+U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ricardo Neri , Giovanni Gherdovich , "Peter Zijlstra (Intel)" , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 5.7 008/393] x86, sched: Bail out of frequency invariance if turbo frequency is unknown Date: Mon, 17 Aug 2020 17:10:58 +0200 Message-Id: <20200817143819.989905377@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143819.579311991@linuxfoundation.org> References: <20200817143819.579311991@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Giovanni Gherdovich [ Upstream commit 51beea8862a3095559862df39554f05042e1195b ] There may be CPUs that support turbo boost but don't declare any turbo ratio, i.e. their MSR_TURBO_RATIO_LIMIT is all zeroes. In that condition scale-invariant calculations can't be performed. Fixes: 1567c3e3467c ("x86, sched: Add support for frequency invariance") Suggested-by: Ricardo Neri Signed-off-by: Giovanni Gherdovich Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Rafael J. Wysocki Tested-by: Ricardo Neri Link: https://lkml.kernel.org/r/20200531182453.15254-3-ggherdovich@suse.cz Signed-off-by: Sasha Levin --- arch/x86/kernel/smpboot.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 2f24c334a938b..3917a2de1580c 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1999,9 +1999,11 @@ static bool intel_set_max_freq_ratio(void) /* * Some hypervisors advertise X86_FEATURE_APERFMPERF * but then fill all MSR's with zeroes. + * Some CPUs have turbo boost but don't declare any turbo ratio + * in MSR_TURBO_RATIO_LIMIT. */ - if (!base_freq) { - pr_debug("Couldn't determine cpu base frequency, necessary for scale-invariant accounting.\n"); + if (!base_freq || !turbo_freq) { + pr_debug("Couldn't determine cpu base or turbo frequency, necessary for scale-invariant accounting.\n"); return false; } -- 2.25.1