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,URIBL_BLOCKED, 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 98C1FC433DF for ; Mon, 17 Aug 2020 19:51:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 64C7220658 for ; Mon, 17 Aug 2020 19:51:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597693901; bh=76s7D4MfERblX/4AMHImA7rzFqIClB7ILCfxPsJZtjI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gWXm7JA5m4WdaW86VnJHa5d/lpafHXHwWy2QbhR1zw4H7awBzurGscFoAZKrD5yKP AHJ99PD976lh9L0xzL6MOlFHXJ8ypDTHJSLL4t5humCmcKEY2XBe9ETXudDWQ5Zecv r53gKnsii/BLQwF4fm5eFvejJ+/+9AECzR1+GFjo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404459AbgHQTvi (ORCPT ); Mon, 17 Aug 2020 15:51:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:40142 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729126AbgHQPSf (ORCPT ); Mon, 17 Aug 2020 11:18:35 -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 7312E20709; Mon, 17 Aug 2020 15:18:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597677514; bh=76s7D4MfERblX/4AMHImA7rzFqIClB7ILCfxPsJZtjI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=snLMlLpcAzDonh+fgvEw1EK0SA/tpR5ZD/GUcyowmelDqA1CakTKp7tw83FZ3hZRv ncxIRECNzP0hjjIWl8gGxga6HzlVLNeH3hQdO/ztjJzjqTNMrUoWIWKSou/UEdGo5E V28jGfwlmfNp5XAC8ZlA7a42vqqnwWR8q7RNfcyI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Giovanni Gherdovich , "Peter Zijlstra (Intel)" , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 5.8 011/464] x86, sched: Bail out of frequency invariance if turbo_freq/base_freq gives 0 Date: Mon, 17 Aug 2020 17:09:24 +0200 Message-Id: <20200817143834.296104724@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143833.737102804@linuxfoundation.org> References: <20200817143833.737102804@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 f4291df103315a696f0b8c4f45ca8ae773c17441 ] 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 Signed-off-by: Sasha Levin --- 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 20e1cea262e4b..518ac6bf752e0 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 @@ static bool intel_set_max_freq_ratio(void) 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; } -- 2.25.1