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From: Frederic Weisbecker <frederic@kernel.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Frederic Weisbecker <frederic@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Chris Metcalf <cmetcalf@mellanox.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Luiz Capitulino <lcapitulino@redhat.com>,
	Christoph Lameter <cl@linux.com>,
	"Paul E . McKenney" <paulmck@linux.vnet.ibm.com>,
	Mike Galbraith <efault@gmx.de>, Rik van Riel <riel@redhat.com>,
	Wanpeng Li <kernellwp@gmail.com>
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> (raw)
In-Reply-To: <1509072159-31808-1-git-send-email-frederic@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 <frederic@kernel.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wanpeng Li <kernellwp@gmail.com>
---
 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 <linux/tick.h>
 
 #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 <linux/tick.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/static_key.h>
 
+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

  parent reply index

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-27  2:42 [GIT PULL] Housekeeping subsystem v6 Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 01/12] housekeeping: Move housekeeping related code to its own file Frederic Weisbecker
2017-10-27 12:01   ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 02/12] watchdog: Use housekeeping_cpumask() instead of ad-hoc version Frederic Weisbecker
2017-10-27 12:02   ` [tip:sched/core] sched/isolation, " tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 03/12] housekeeping: Provide a dynamic off-case to housekeeping_any_cpu() Frederic Weisbecker
2017-10-27 12:02   ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 04/12] housekeeping: Make housekeeping cpumask private Frederic Weisbecker
2017-10-27 12:03   ` [tip:sched/core] sched/isolation: Make the " tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` Frederic Weisbecker [this message]
2017-10-27 12:03   ` [tip:sched/core] sched/isolation: Use its own static key tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 06/12] housekeeping: Rename is_housekeeping_cpu to housekeeping_cpu Frederic Weisbecker
2017-10-27 12:03   ` [tip:sched/core] sched/isolation: Rename is_housekeeping_cpu() to housekeeping_cpu() tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 07/12] housekeeping: Move it under its own config, independent from NO_HZ Frederic Weisbecker
2017-10-27 12:04   ` [tip:sched/core] sched/isolation: Split out new CONFIG_CPU_ISOLATION=y config from CONFIG_NO_HZ_FULL tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 08/12] housekeeping: Introduce housekeeping flags Frederic Weisbecker
2017-10-27 12:04   ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 09/12] housekeeping: Handle the nohz_full= parameter Frederic Weisbecker
2017-10-27 12:05   ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 10/12] housekeeping: Move isolcpus to housekeeping Frederic Weisbecker
2017-10-27 12:05   ` [tip:sched/core] sched/isolation: Move isolcpus= handling to the housekeeping code tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 11/12] housekeeping: Add basic isolcpus flags Frederic Weisbecker
2017-10-27 12:05   ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 12/12] housekeeping: Document " Frederic Weisbecker
2017-10-27 12:06   ` [tip:sched/core] sched/isolation: Document the isolcpus= flags tip-bot for Frederic Weisbecker
2017-10-27 13:58     ` Peter Zijlstra
2017-10-27 14:36       ` Frederic Weisbecker
2017-10-27 17:06         ` Ingo Molnar
2017-10-27 17:33           ` Frederic Weisbecker
2017-10-27 18:21             ` Ingo Molnar
2017-10-27 18:39               ` Frederic Weisbecker
2017-10-27 19:04                 ` Ingo Molnar
2017-10-27 14:38       ` Mike Galbraith
2017-10-30 15:48       ` Christopher Lameter
2017-10-30 16:11         ` Peter Zijlstra
2017-10-30 16:30           ` Christopher Lameter
2017-10-30 16:58             ` Peter Zijlstra
2017-10-30 16:56           ` Mike Galbraith
  -- strict thread matches above, loose matches on Subject: below --
2017-10-24 13:06 [GIT PULL] Introduce housekeeping subsystem v5 Frederic Weisbecker
2017-10-24 13:06 ` [PATCH 05/12] housekeeping: Use its own static key Frederic Weisbecker
2017-09-18 13:53 [GIT PULL] Introduce housekeeping subsystem v4 Frederic Weisbecker
2017-09-18 13:54 ` [PATCH 05/12] housekeeping: Use its own static key Frederic Weisbecker
2017-09-01 16:41 [PATCH 00/12] Introduce housekeeping subsystem v3 Frederic Weisbecker
2017-09-01 16:41 ` [PATCH 05/12] housekeeping: Use its own static key Frederic Weisbecker

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