Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753302AbdHWBx3 (ORCPT ); Tue, 22 Aug 2017 21:53:29 -0400 Received: from mail-wr0-f193.google.com ([209.85.128.193]:38375 "EHLO mail-wr0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753274AbdHWBv1 (ORCPT ); Tue, 22 Aug 2017 21:51:27 -0400 From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Peter Zijlstra , Chris Metcalf , Thomas Gleixner , Luiz Capitulino , Christoph Lameter , "Paul E . McKenney" , Ingo Molnar , Mike Galbraith , Rik van Riel , Wanpeng Li Subject: [RFC PATCH 05/12] housekeeping: Use its own static key Date: Wed, 23 Aug 2017 03:51:04 +0200 Message-Id: <1503453071-952-6-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1503453071-952-1-git-send-email-fweisbec@gmail.com> References: <1503453071-952-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3305 Lines: 105 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: Rik van Riel Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Mike Galbraith Cc: Ingo Molnar Cc: Christoph Lameter Cc: Paul E. McKenney Cc: Wanpeng Li Cc: Luiz Capitulino --- include/linux/housekeeping.h | 3 ++- kernel/housekeeping.c | 14 +++++++++----- 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/include/linux/housekeeping.h b/include/linux/housekeeping.h index 31a1401..cbe8d63 100644 --- a/include/linux/housekeeping.h +++ b/include/linux/housekeeping.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/housekeeping.c b/kernel/housekeeping.c index 0183e75..f8be7e6 100644 --- a/kernel/housekeeping.c +++ b/kernel/housekeeping.c @@ -9,12 +9,15 @@ #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(); @@ -22,7 +25,7 @@ int housekeeping_any_cpu(void) const struct cpumask *housekeeping_cpumask(void) { - if (tick_nohz_full_enabled()) + if (static_branch_unlikely(&housekeeping_overriden)) return housekeeping_mask; return cpu_possible_mask; @@ -30,19 +33,18 @@ const struct cpumask *housekeeping_cpumask(void) 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); } 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; } - void __init housekeeping_init(void) { if (!tick_nohz_full_enabled()) @@ -58,6 +60,8 @@ 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