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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 03466C433E3 for ; Sat, 8 Aug 2020 23:51:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CBD3420672 for ; Sat, 8 Aug 2020 23:51:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596930700; bh=3SszuFnMRkh91EddoT1fiCaR7YvhFDLhQ6A0QGRX8Ro=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=CVlCNH7mzYLd+FfC3N5uWI8IYA46LzcIqxQJi+oK8EnMSCD1wiOGkoUxFJ48wlqxA 0ZjhJw6aUpfqCz7iip3JNMLhCkmD/Xn6CFaa9CCofXOC1DK4q75euRQkhLKTwwhGcM zNN5x+gUtodmSE8KpMm6aAjEgyxjRogfKBTUo4kU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726472AbgHHXfz (ORCPT ); Sat, 8 Aug 2020 19:35:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:48064 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726398AbgHHXfv (ORCPT ); Sat, 8 Aug 2020 19:35:51 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3A7A7206D8; Sat, 8 Aug 2020 23:35:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596929751; bh=3SszuFnMRkh91EddoT1fiCaR7YvhFDLhQ6A0QGRX8Ro=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0hH8xFtHk5Hdk3/dmJYZhxQfTsKtKRHSJRPPIETly5j5sNUOhy0Bs8UktHmczmoI6 6xErPRi9GxOpLFEHLy+I9fxdpPDEnUDS0lAPoXEr5g7cXEQONNU/RK9YRDjVgJnkGx YtM5j9eVoTfAqZuKX6OXnkKKw1JnlDDBlDi3hotg= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Giovanni Gherdovich , Ricardo Neri , Peter Zijlstra , "Rafael J . Wysocki" , Sasha Levin Subject: [PATCH AUTOSEL 5.8 06/72] x86, sched: Bail out of frequency invariance if turbo frequency is unknown Date: Sat, 8 Aug 2020 19:34:35 -0400 Message-Id: <20200808233542.3617339-6-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200808233542.3617339-1-sashal@kernel.org> References: <20200808233542.3617339-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 18d292fc466cb..20e1cea262e4b 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -2002,9 +2002,11 @@ 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