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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=no 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 C025DC433DF for ; Sun, 31 May 2020 18:26:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D8902074B for ; Sun, 31 May 2020 18:26:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728337AbgEaS0P (ORCPT ); Sun, 31 May 2020 14:26:15 -0400 Received: from mx2.suse.de ([195.135.220.15]:52360 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726008AbgEaS0O (ORCPT ); Sun, 31 May 2020 14:26:14 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id E0261AC79; Sun, 31 May 2020 18:26:13 +0000 (UTC) From: Giovanni Gherdovich To: Srinivas Pandruvada , Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Borislav Petkov , "Rafael J . Wysocki" Cc: x86@kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Ricardo Neri , Giovanni Gherdovich Subject: [PATCH v2 0/3] More frequency invariance fixes for x86 Date: Sun, 31 May 2020 20:24:50 +0200 Message-Id: <20200531182453.15254-1-ggherdovich@suse.cz> X-Mailer: git-send-email 2.16.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org v1 at https://lore.kernel.org/lkml/20200428132450.24901-1-ggherdovich@suse.cz/ changes wrt v1: - add Peter Zijlstra's code to check for multiplication overflow, see https://lore.kernel.org/lkml/20200501133042.GE3762@hirez.programming.kicks-ass.net/ - put all frequence invariant code behind CONFIG_X86_64, as the overflow checks need 64 bits operations, see the build error at https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org/thread/7GDIBOMNVDG5W2XZD4EICE2TUZR3THBN/ - add additional patch to check for when base_freq > turbo_freq, suggested by Peter Zijlstra at https://lore.kernel.org/lkml/20200501130427.GD3762@hirez.programming.kicks-ass.net/ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Cover Letter from v1: Patch 1/2 prevents a division by zero in case the product "delta_MPERF * arch_max_freq_ratio" overflows u64, as suggested by Linus at [1]. This patch supersedes the version at [2], as it also disables frequency invariance when that overflow happens. Patch 2/2 implements the recommendation by Ricardo Neri to check for an all zero MSR_TURBO_RATIO_LIMIT and disable freq invariance in that case too. [1] https://lore.kernel.org/lkml/CAHk-=wiX+NT2yxtdPszH9U_S96MCNQA56GJFXY45mZc47yG5KQ@mail.gmail.com/ [2] https://lore.kernel.org/lkml/20200422144055.18171-1-ggherdovich@suse.cz/ [3] https://lore.kernel.org/lkml/20200424013222.GA26355@ranerica-svr.sc.intel.com/ Giovanni Gherdovich (3): x86, sched: check for counters overflow in frequency invariant accounting x86, sched: Bail out of frequency invariance if turbo frequency is unknown x86, sched: Bail out of frequency invariance if turbo_freq/base_freq gives 0 arch/x86/include/asm/topology.h | 2 +- arch/x86/kernel/smpboot.c | 50 +++++++++++++++++++++++++++++++++-------- 2 files changed, 42 insertions(+), 10 deletions(-) -- 2.16.4