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=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 683CCC433E0 for ; Tue, 16 Jun 2020 12:22:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A93D214F1 for ; Tue, 16 Jun 2020 12:22:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729242AbgFPMWx (ORCPT ); Tue, 16 Jun 2020 08:22:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42752 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729027AbgFPMWM (ORCPT ); Tue, 16 Jun 2020 08:22:12 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1A8D5C08C5C3; Tue, 16 Jun 2020 05:22:12 -0700 (PDT) Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jlAbO-0004jC-UJ; Tue, 16 Jun 2020 14:22:07 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 9DDA91C0475; Tue, 16 Jun 2020 14:21:54 +0200 (CEST) Date: Tue, 16 Jun 2020 12:21:54 -0000 From: "tip-bot2 for Giovanni Gherdovich" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] x86, sched: Bail out of frequency invariance if turbo_freq/base_freq gives 0 Cc: Giovanni Gherdovich , "Peter Zijlstra (Intel)" , "Rafael J. Wysocki" , x86 , LKML In-Reply-To: <20200531182453.15254-4-ggherdovich@suse.cz> References: <20200531182453.15254-4-ggherdovich@suse.cz> MIME-Version: 1.0 Message-ID: <159231011443.16989.10180990349083727311.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the sched/core branch of tip: Commit-ID: f4291df103315a696f0b8c4f45ca8ae773c17441 Gitweb: https://git.kernel.org/tip/f4291df103315a696f0b8c4f45ca8ae773c17441 Author: Giovanni Gherdovich AuthorDate: Sun, 31 May 2020 20:24:53 +02:00 Committer: Peter Zijlstra CommitterDate: Mon, 15 Jun 2020 14:10:02 +02:00 x86, sched: Bail out of frequency invariance if turbo_freq/base_freq gives 0 Be defensive against the case where the processor reports a base_freq larger than turbo_freq (the ratio would be zero). Fixes: 1567c3e3467c ("x86, sched: Add support for frequency invariance") Signed-off-by: Giovanni Gherdovich Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Rafael J. Wysocki Link: https://lkml.kernel.org/r/20200531182453.15254-4-ggherdovich@suse.cz --- arch/x86/kernel/smpboot.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 20e1cea..518ac6b 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1977,6 +1977,7 @@ static bool core_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq) static bool intel_set_max_freq_ratio(void) { u64 base_freq, turbo_freq; + u64 turbo_ratio; if (slv_set_max_freq_ratio(&base_freq, &turbo_freq)) goto out; @@ -2010,9 +2011,15 @@ out: return false; } - arch_turbo_freq_ratio = div_u64(turbo_freq * SCHED_CAPACITY_SCALE, - base_freq); + turbo_ratio = div_u64(turbo_freq * SCHED_CAPACITY_SCALE, base_freq); + if (!turbo_ratio) { + pr_debug("Non-zero turbo and base frequencies led to a 0 ratio.\n"); + return false; + } + + arch_turbo_freq_ratio = turbo_ratio; arch_set_max_freq_ratio(turbo_disabled()); + return true; }