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=unavailable 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 4E3BBC433DF for ; Sat, 8 Aug 2020 23:48:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B402206B5 for ; Sat, 8 Aug 2020 23:48:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596930496; bh=G5K0RJa7nYZUNphGIKeV64484sMdLIh3FAx+a8erWrg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FXpfwXn/QGFlYfpgfjetJ45XfGlKCQYCPuN/DHfzZ5LOxnNO4B0iVpiulD0wNGNGZ CLe+uFStIZAAmqZ2IjKvyJiJRTNp8k+PbmC0EEmCuQ3Okfpn2XxBvJCutFRlEfBg89 EhHAe6nPfaIp1ANsD1zYzYLX725li5y0gPL4Uso4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728490AbgHHXsN (ORCPT ); Sat, 8 Aug 2020 19:48:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:50626 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727985AbgHHXhb (ORCPT ); Sat, 8 Aug 2020 19:37:31 -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 5F18A207BB; Sat, 8 Aug 2020 23:37:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596929851; bh=G5K0RJa7nYZUNphGIKeV64484sMdLIh3FAx+a8erWrg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TyjTSw9Spthazbkj1ksAhzzcw4YUDRduDYUCkoQBx/x53uls2ziUvVX2eOlXillBx sact/PJoYO9FyLpVS+80Bt0eSkiEZNFzZWiEBsq2NeBKCBS2F/COqIwX7GbQrb65XY aaN5Qcppnc1cOJCUPoLttHceQOt+VNdXHHShg1Zo= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Giovanni Gherdovich , Peter Zijlstra , "Rafael J . Wysocki" , Sasha Levin Subject: [PATCH AUTOSEL 5.7 05/58] x86, sched: Bail out of frequency invariance if turbo_freq/base_freq gives 0 Date: Sat, 8 Aug 2020 19:36:31 -0400 Message-Id: <20200808233724.3618168-5-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200808233724.3618168-1-sashal@kernel.org> References: <20200808233724.3618168-1-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 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 3917a2de1580c..e5b2b20a0aeee 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1974,6 +1974,7 @@ 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; @@ -2007,9 +2008,15 @@ 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