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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: linux-kernel@vger.kernel.org
Cc: rt@linuxtronix.de, Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: [PATCH 13/20] sched/nohz: Convert to hotplug state machine
Date: Thu, 17 Nov 2016 19:35:34 +0100
Message-ID: <20161117183541.8588-14-bigeasy@linutronix.de> (raw)
In-Reply-To: <20161117183541.8588-1-bigeasy@linutronix.de>

Install the callbacks via the state machine.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 kernel/time/tick-sched.c | 33 ++++++++++++++-------------------
 1 file changed, 14 insertions(+), 19 deletions(-)

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 3bcb61b52f6c..420da0749792 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -390,24 +390,16 @@ static int __init tick_nohz_full_setup(char *str)
 }
 __setup("nohz_full=", tick_nohz_full_setup);
 
-static int tick_nohz_cpu_down_callback(struct notifier_block *nfb,
-				       unsigned long action,
-				       void *hcpu)
+static int tick_nohz_cpu_down(unsigned int cpu)
 {
-	unsigned int cpu = (unsigned long)hcpu;
-
-	switch (action & ~CPU_TASKS_FROZEN) {
-	case CPU_DOWN_PREPARE:
-		/*
-		 * The boot CPU handles housekeeping duty (unbound timers,
-		 * workqueues, timekeeping, ...) on behalf of full dynticks
-		 * CPUs. It must remain online when nohz full is enabled.
-		 */
-		if (tick_nohz_full_running && tick_do_timer_cpu == cpu)
-			return NOTIFY_BAD;
-		break;
-	}
-	return NOTIFY_OK;
+	/*
+	 * The boot CPU handles housekeeping duty (unbound timers,
+	 * workqueues, timekeeping, ...) on behalf of full dynticks
+	 * CPUs. It must remain online when nohz full is enabled.
+	 */
+	if (tick_nohz_full_running && tick_do_timer_cpu == cpu)
+		return -EINVAL;
+	return 0;
 }
 
 static int tick_nohz_init_all(void)
@@ -428,7 +420,7 @@ static int tick_nohz_init_all(void)
 
 void __init tick_nohz_init(void)
 {
-	int cpu;
+	int cpu, ret;
 
 	if (!tick_nohz_full_running) {
 		if (tick_nohz_init_all() < 0)
@@ -469,7 +461,10 @@ void __init tick_nohz_init(void)
 	for_each_cpu(cpu, tick_nohz_full_mask)
 		context_tracking_cpu_set(cpu);
 
-	cpu_notifier(tick_nohz_cpu_down_callback, 0);
+	ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+					"kernel/nohz:predown", NULL,
+					tick_nohz_cpu_down);
+	WARN_ON(ret < 0);
 	pr_info("NO_HZ: Full dynticks CPUs: %*pbl.\n",
 		cpumask_pr_args(tick_nohz_full_mask));
 
-- 
2.10.2

  parent reply index

Thread overview: 94+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-17 18:35 cpu hotplug: convert more drivers (batch #5) Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 01/20] x86/mce/therm_throt: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-11-21 15:46   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:39   ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 02/20] x86/cpuid: " Sebastian Andrzej Siewior
2016-11-21 15:47   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:40   ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 03/20] x86/msr: " Sebastian Andrzej Siewior
2016-11-21 15:48   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:41   ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 04/20] hwmon/coretemp: " Sebastian Andrzej Siewior
2016-11-20 22:30   ` [04/20] " Guenter Roeck
2016-11-21 22:35     ` Sebastian Andrzej Siewior
2016-11-21 15:56   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-21 21:32     ` Guenter Roeck
2016-11-21 21:53       ` Thomas Gleixner
2016-11-17 18:35 ` [PATCH 05/20] hwmon/via-cputemp: Remove pointless CPU check on each CPU Sebastian Andrzej Siewior
2016-11-19 17:23   ` [05/20] " Guenter Roeck
2016-11-19 22:53     ` Sebastian Andrzej Siewior
2016-11-20  3:53       ` Guenter Roeck
2016-11-20 20:34         ` Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 06/20] hwmon/via-cputemp: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-11-18 15:09   ` [PATCH 06/20 v2] " Sebastian Andrzej Siewior
2016-11-23 15:29   ` [PATCH 06/20] " Guenter Roeck
2016-12-09 11:53   ` Thomas Gleixner
2016-12-09 18:17     ` Guenter Roeck
2016-12-09 18:27       ` Thomas Gleixner
2016-11-17 18:35 ` [PATCH 07/20] pci/xgene-msi: " Sebastian Andrzej Siewior
2016-11-21 15:48   ` [tip:smp/hotplug] PCI/xgene-msi: " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:42   ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 08/20] powercap/intel_rapl: Add missing domain data update on hotplug Sebastian Andrzej Siewior
2016-11-21 15:49   ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2016-11-17 18:35 ` [PATCH 09/20] powercap/intel rapl: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-11-21 15:49   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 10/20] powercap/intel_rapl: Cleanup duplicated init code Sebastian Andrzej Siewior
2016-11-21 15:50   ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2016-11-17 18:35 ` [PATCH 11/20] watchdog/octeon: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-11-21 15:50   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:43   ` tip-bot for Sebastian Andrzej Siewior
2016-11-24 16:10   ` [11/20] " Guenter Roeck
2016-11-17 18:35 ` [PATCH 12/20] net/iucv: " Sebastian Andrzej Siewior
2016-11-21 15:51   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:43   ` tip-bot for Sebastian Andrzej Siewior
2016-11-23 18:04   ` [PATCH 12/20] " Ursula Braun
2016-11-24  9:10     ` Sebastian Andrzej Siewior
2016-11-24 14:14       ` [PATCH 12/20 v2] " Sebastian Andrzej Siewior
2016-11-24 16:10         ` [PATCH] net/iucv: use explicit clean up labels in iucv_init() Sebastian Andrzej Siewior
2016-11-24 19:57           ` [tip:smp/hotplug] net/iucv: Use " tip-bot for Sebastian Andrzej Siewior
2016-11-28 16:24           ` [PATCH] net/iucv: use " David Miller
2016-11-28 16:31             ` Thomas Gleixner
2016-11-28 16:37           ` [tip:smp/hotplug] net/iucv: Use " tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` Sebastian Andrzej Siewior [this message]
2016-11-21 15:51   ` [tip:smp/hotplug] sched/nohz: Convert to hotplug state machine tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:44   ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 14/20] arm/bL_switcher: " Sebastian Andrzej Siewior
2016-11-21 15:52   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:44   ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 15/20] ARM/hw_breakpoint: " Sebastian Andrzej Siewior
2016-11-18 12:04   ` Will Deacon
2016-11-18 13:11     ` Thomas Gleixner
2016-11-18 13:29       ` Will Deacon
2016-11-18 13:42         ` Thomas Gleixner
2016-11-18 13:48           ` Will Deacon
2016-11-18 13:59             ` Thomas Gleixner
2016-11-18 14:11               ` Will Deacon
2016-11-21 15:52   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:45   ` tip-bot for Sebastian Andrzej Siewior
2017-01-02 14:15   ` [PATCH 15/20] " Linus Walleij
2017-01-02 14:34     ` Linus Walleij
2017-01-02 15:00       ` Russell King - ARM Linux
2017-01-02 20:15         ` Linus Walleij
2017-01-03  9:33           ` Mark Rutland
2017-01-04 11:27             ` Sebastian Andrzej Siewior
2017-01-04 13:56             ` Mark Rutland
2017-01-04 14:32               ` Will Deacon
2017-01-05 15:57                 ` Mark Rutland
2017-01-05 15:26               ` Linus Walleij
2017-01-05 17:14                 ` Mark Rutland
2016-11-17 18:35 ` [PATCH 16/20] powerpc/sysfs: " Sebastian Andrzej Siewior
2016-11-21 15:53   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:45   ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 17/20] sparc/sysfs: " Sebastian Andrzej Siewior
2016-11-17 18:39   ` David Miller
2016-11-21 15:54   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:46   ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 18/20] x86/oprofile/nmi: Remove superfluous smp_function_call_single() Sebastian Andrzej Siewior
2016-11-21 15:54   ` [tip:smp/hotplug] " tip-bot for Anna-Maria Gleixner
2016-11-22 22:46   ` tip-bot for Anna-Maria Gleixner
2016-11-17 18:35 ` [PATCH 19/20] x86/oprofile/nmi: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-11-21 15:55   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:47   ` tip-bot for Sebastian Andrzej Siewior
2016-11-17 18:35 ` [PATCH 20/20] x86/pci/amd-bus: " Sebastian Andrzej Siewior
2016-11-21 15:55   ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-22 22:47   ` tip-bot for Sebastian Andrzej Siewior

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