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 CA1BEC33C9E for ; Fri, 17 Jan 2020 18:41:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ACB072072B for ; Fri, 17 Jan 2020 18:41:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729370AbgAQSlq (ORCPT ); Fri, 17 Jan 2020 13:41:46 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:57330 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726935AbgAQSlp (ORCPT ); Fri, 17 Jan 2020 13:41:45 -0500 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 1isWYr-0006WV-N7; Fri, 17 Jan 2020 19:41:37 +0100 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 437AC1C19F0; Fri, 17 Jan 2020 19:41:37 +0100 (CET) Date: Fri, 17 Jan 2020 18:41:37 -0000 From: "tip-bot2 for Xiaochen Shen" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/cache] x86/resctrl: Check monitoring static key in the MBM overflow handler Cc: Xiaochen Shen , Borislav Petkov , x86 , LKML In-Reply-To: <1576094705-13660-1-git-send-email-xiaochen.shen@intel.com> References: <1576094705-13660-1-git-send-email-xiaochen.shen@intel.com> MIME-Version: 1.0 Message-ID: <157928649703.396.16058225567355678427.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 x86/cache branch of tip: Commit-ID: 536a0d8e79fb928f2735db37dda95682b6754f9a Gitweb: https://git.kernel.org/tip/536a0d8e79fb928f2735db37dda95682b6754f9a Author: Xiaochen Shen AuthorDate: Thu, 12 Dec 2019 04:05:05 +08:00 Committer: Borislav Petkov CommitterDate: Fri, 17 Jan 2020 19:32:32 +01:00 x86/resctrl: Check monitoring static key in the MBM overflow handler Currently, there are three static keys in the resctrl file system: rdt_mon_enable_key and rdt_alloc_enable_key indicate if the monitoring feature and the allocation feature are enabled, respectively. The rdt_enable_key is enabled when either the monitoring feature or the allocation feature is enabled. If no monitoring feature is present (either hardware doesn't support a monitoring feature or the feature is disabled by the kernel command line option "rdt="), rdt_enable_key is still enabled but rdt_mon_enable_key is disabled. MBM is a monitoring feature. The MBM overflow handler intends to check if the monitoring feature is not enabled for fast return. So check the rdt_mon_enable_key in it instead of the rdt_enable_key as former is the more accurate check. [ bp: Massage commit message. ] Fixes: e33026831bdb ("x86/intel_rdt/mbm: Handle counter overflow") Signed-off-by: Xiaochen Shen Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/1576094705-13660-1-git-send-email-xiaochen.shen@intel.com --- arch/x86/kernel/cpu/resctrl/internal.h | 1 + arch/x86/kernel/cpu/resctrl/monitor.c | 4 ++-- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index e49b772..181c992 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -57,6 +57,7 @@ static inline struct rdt_fs_context *rdt_fc2context(struct fs_context *fc) } DECLARE_STATIC_KEY_FALSE(rdt_enable_key); +DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key); /** * struct mon_evt - Entry in the event list of a resource diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 397206f..773124b 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -514,7 +514,7 @@ void mbm_handle_overflow(struct work_struct *work) mutex_lock(&rdtgroup_mutex); - if (!static_branch_likely(&rdt_enable_key)) + if (!static_branch_likely(&rdt_mon_enable_key)) goto out_unlock; d = get_domain_from_cpu(cpu, &rdt_resources_all[RDT_RESOURCE_L3]); @@ -543,7 +543,7 @@ void mbm_setup_overflow_handler(struct rdt_domain *dom, unsigned long delay_ms) unsigned long delay = msecs_to_jiffies(delay_ms); int cpu; - if (!static_branch_likely(&rdt_enable_key)) + if (!static_branch_likely(&rdt_mon_enable_key)) return; cpu = cpumask_any(&dom->cpu_mask); dom->mbm_work_cpu = cpu;