From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932507AbdJ0Coq (ORCPT ); Thu, 26 Oct 2017 22:44:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:37824 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932484AbdJ0CnD (ORCPT ); Thu, 26 Oct 2017 22:43:03 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 75A5121939 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=frederic@kernel.org From: Frederic Weisbecker To: Ingo Molnar Cc: LKML , Frederic Weisbecker , Peter Zijlstra , Linus Torvalds , Chris Metcalf , Thomas Gleixner , Luiz Capitulino , Christoph Lameter , "Paul E . McKenney" , Mike Galbraith , Rik van Riel , Wanpeng Li Subject: [PATCH 05/12] housekeeping: Use its own static key Date: Fri, 27 Oct 2017 04:42:32 +0200 Message-Id: <1509072159-31808-6-git-send-email-frederic@kernel.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1509072159-31808-1-git-send-email-frederic@kernel.org> References: <1509072159-31808-1-git-send-email-frederic@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Housekeeping code still depends on nohz_full static key. Since we want to decouple housekeeping from nohz, let's create a housekeeping own static key. It's mostly relevant for calls to is_housekeeping_cpu() from the scheduler. Signed-off-by: Frederic Weisbecker Cc: Chris Metcalf Cc: Christoph Lameter Cc: Linus Torvalds Cc: Luiz Capitulino Cc: Mike Galbraith Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: Wanpeng Li --- include/linux/sched/isolation.h | 3 ++- kernel/sched/isolation.c | 13 +++++++++---- 2 files changed, 11 insertions(+), 5 deletions(-) diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h index ed935ff..194c586 100644 --- a/include/linux/sched/isolation.h +++ b/include/linux/sched/isolation.h @@ -6,6 +6,7 @@ #include #ifdef CONFIG_NO_HZ_FULL +DECLARE_STATIC_KEY_FALSE(housekeeping_overriden); extern int housekeeping_any_cpu(void); extern const struct cpumask *housekeeping_cpumask(void); extern void housekeeping_affine(struct task_struct *t); @@ -31,7 +32,7 @@ static inline void housekeeping_init(void) { } static inline bool is_housekeeping_cpu(int cpu) { #ifdef CONFIG_NO_HZ_FULL - if (tick_nohz_full_enabled()) + if (static_branch_unlikely(&housekeeping_overriden)) return housekeeping_test_cpu(cpu); #endif return true; diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index 1644509..bb8ba19 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -10,12 +10,15 @@ #include #include #include +#include +DEFINE_STATIC_KEY_FALSE(housekeeping_overriden); +EXPORT_SYMBOL_GPL(housekeeping_overriden); static cpumask_var_t housekeeping_mask; int housekeeping_any_cpu(void) { - if (tick_nohz_full_enabled()) + if (static_branch_unlikely(&housekeeping_overriden)) return cpumask_any_and(housekeeping_mask, cpu_online_mask); return smp_processor_id(); @@ -24,7 +27,7 @@ EXPORT_SYMBOL_GPL(housekeeping_any_cpu); const struct cpumask *housekeeping_cpumask(void) { - if (tick_nohz_full_enabled()) + if (static_branch_unlikely(&housekeeping_overriden)) return housekeeping_mask; return cpu_possible_mask; @@ -33,14 +36,14 @@ EXPORT_SYMBOL_GPL(housekeeping_cpumask); void housekeeping_affine(struct task_struct *t) { - if (tick_nohz_full_enabled()) + if (static_branch_unlikely(&housekeeping_overriden)) set_cpus_allowed_ptr(t, housekeeping_mask); } EXPORT_SYMBOL_GPL(housekeeping_affine); bool housekeeping_test_cpu(int cpu) { - if (tick_nohz_full_enabled()) + if (static_branch_unlikely(&housekeeping_overriden)) return cpumask_test_cpu(cpu, housekeeping_mask); return true; @@ -62,6 +65,8 @@ void __init housekeeping_init(void) cpumask_andnot(housekeeping_mask, cpu_possible_mask, tick_nohz_full_mask); + static_branch_enable(&housekeeping_overriden); + /* We need at least one CPU to handle housekeeping work */ WARN_ON_ONCE(cpumask_empty(housekeeping_mask)); } -- 2.7.4