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Groups > linux.kernel > #1344567
| From | Thomas Gleixner <tglx@linutronix.de> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [patch 02/20] cpu/hotplug: Restructure FROZEN state handling |
| Date | 2016-02-26 19:50 +0100 |
| Message-ID | <r6vCH-7sv-27@gated-at.bofh.it> (permalink) |
| References | <r6vCG-7sv-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
There are only a few callbacks which really care about FROZEN
vs. !FROZEN. No need to have extra states for this.
Publish the frozen state in an extra variable which is updated under
the hotplug lock and let the users interested deal with it w/o
imposing that extra state checks on everyone.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
include/linux/cpu.h | 2 +
kernel/cpu.c | 69 +++++++++++++++++++++-------------------------------
2 files changed, 31 insertions(+), 40 deletions(-)
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -118,6 +118,7 @@ enum {
#ifdef CONFIG_SMP
+extern bool cpuhp_tasks_frozen;
/* Need to know about CPUs going up/down? */
#if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
#define cpu_notifier(fn, pri) { \
@@ -177,6 +178,7 @@ extern void cpu_maps_update_done(void);
#define cpu_notifier_register_done cpu_maps_update_done
#else /* CONFIG_SMP */
+#define cpuhp_tasks_frozen 0
#define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
#define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -29,6 +29,8 @@
#ifdef CONFIG_SMP
/* Serializes the updates to cpu_online_mask, cpu_present_mask */
static DEFINE_MUTEX(cpu_add_remove_lock);
+bool cpuhp_tasks_frozen;
+EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen);
/*
* The following two APIs (cpu_maps_update_begin/done) must be used when
@@ -207,27 +209,30 @@ int __register_cpu_notifier(struct notif
return raw_notifier_chain_register(&cpu_chain, nb);
}
-static int __cpu_notify(unsigned long val, void *v, int nr_to_call,
+static int __cpu_notify(unsigned long val, unsigned int cpu, int nr_to_call,
int *nr_calls)
{
+ unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0;
+ void *hcpu = (void *)(long)cpu;
+
int ret;
- ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call,
+ ret = __raw_notifier_call_chain(&cpu_chain, val | mod, hcpu, nr_to_call,
nr_calls);
return notifier_to_errno(ret);
}
-static int cpu_notify(unsigned long val, void *v)
+static int cpu_notify(unsigned long val, unsigned int cpu)
{
- return __cpu_notify(val, v, -1, NULL);
+ return __cpu_notify(val, cpu, -1, NULL);
}
#ifdef CONFIG_HOTPLUG_CPU
-static void cpu_notify_nofail(unsigned long val, void *v)
+static void cpu_notify_nofail(unsigned long val, unsigned int cpu)
{
- BUG_ON(cpu_notify(val, v));
+ BUG_ON(cpu_notify(val, cpu));
}
EXPORT_SYMBOL(register_cpu_notifier);
EXPORT_SYMBOL(__register_cpu_notifier);
@@ -311,27 +316,21 @@ static inline void check_for_tasks(int d
read_unlock(&tasklist_lock);
}
-struct take_cpu_down_param {
- unsigned long mod;
- void *hcpu;
-};
-
/* Take this CPU down. */
static int take_cpu_down(void *_param)
{
- struct take_cpu_down_param *param = _param;
- int err;
+ int err, cpu = smp_processor_id();
/* Ensure this CPU doesn't handle any more interrupts. */
err = __cpu_disable();
if (err < 0)
return err;
- cpu_notify(CPU_DYING | param->mod, param->hcpu);
+ cpu_notify(CPU_DYING, cpu);
/* Give up timekeeping duties */
tick_handover_do_timer();
/* Park the stopper thread */
- stop_machine_park((long)param->hcpu);
+ stop_machine_park(cpu);
return 0;
}
@@ -339,12 +338,6 @@ static int take_cpu_down(void *_param)
static int _cpu_down(unsigned int cpu, int tasks_frozen)
{
int err, nr_calls = 0;
- void *hcpu = (void *)(long)cpu;
- unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
- struct take_cpu_down_param tcd_param = {
- .mod = mod,
- .hcpu = hcpu,
- };
if (num_online_cpus() == 1)
return -EBUSY;
@@ -354,10 +347,12 @@ static int _cpu_down(unsigned int cpu, i
cpu_hotplug_begin();
- err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
+ cpuhp_tasks_frozen = tasks_frozen;
+
+ err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls);
if (err) {
nr_calls--;
- __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL);
+ __cpu_notify(CPU_DOWN_FAILED, cpu, nr_calls, NULL);
pr_warn("%s: attempt to take down CPU %u failed\n",
__func__, cpu);
goto out_release;
@@ -389,10 +384,10 @@ static int _cpu_down(unsigned int cpu, i
/*
* So now all preempt/rcu users must observe !cpu_active().
*/
- err = stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
+ err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu));
if (err) {
/* CPU didn't die: tell everyone. Can't complain. */
- cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu);
+ cpu_notify_nofail(CPU_DOWN_FAILED, cpu);
irq_unlock_sparse();
goto out_release;
}
@@ -419,14 +414,14 @@ static int _cpu_down(unsigned int cpu, i
/* CPU is completely dead: tell everyone. Too late to complain. */
tick_cleanup_dead_cpu(cpu);
- cpu_notify_nofail(CPU_DEAD | mod, hcpu);
+ cpu_notify_nofail(CPU_DEAD, cpu);
check_for_tasks(cpu);
out_release:
cpu_hotplug_done();
if (!err)
- cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
+ cpu_notify_nofail(CPU_POST_DEAD, cpu);
return err;
}
@@ -485,10 +480,8 @@ void smpboot_thread_init(void)
/* Requires cpu_add_remove_lock to be held */
static int _cpu_up(unsigned int cpu, int tasks_frozen)
{
- int ret, nr_calls = 0;
- void *hcpu = (void *)(long)cpu;
- unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
struct task_struct *idle;
+ int ret, nr_calls = 0;
cpu_hotplug_begin();
@@ -507,7 +500,9 @@ static int _cpu_up(unsigned int cpu, int
if (ret)
goto out;
- ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls);
+ cpuhp_tasks_frozen = tasks_frozen;
+
+ ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls);
if (ret) {
nr_calls--;
pr_warn("%s: attempt to bring up CPU %u failed\n",
@@ -523,11 +518,11 @@ static int _cpu_up(unsigned int cpu, int
BUG_ON(!cpu_online(cpu));
/* Now call notifier in preparation. */
- cpu_notify(CPU_ONLINE | mod, hcpu);
+ cpu_notify(CPU_ONLINE, cpu);
out_notify:
if (ret != 0)
- __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
+ __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL);
out:
cpu_hotplug_done();
@@ -719,13 +714,7 @@ core_initcall(cpu_hotplug_pm_sync_init);
*/
void notify_cpu_starting(unsigned int cpu)
{
- unsigned long val = CPU_STARTING;
-
-#ifdef CONFIG_PM_SLEEP_SMP
- if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus))
- val = CPU_STARTING_FROZEN;
-#endif /* CONFIG_PM_SLEEP_SMP */
- cpu_notify(val, (void *)(long)cpu);
+ cpu_notify(CPU_STARTING, cpu);
}
#endif /* CONFIG_SMP */
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[patch 00/20] cpu/hotplug: Core infrastructure for cpu hotplug rework Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
[patch 14/20] cpu/hotplug: Split out the state walk into functions Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
[tip:smp/hotplug] cpu/hotplug: Split out the state walk into functions tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
[patch 17/20] arch/hotplug: Call into idle with a proper state Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
[tip:smp/hotplug] arch/hotplug: Call into idle with a proper state tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
[patch 04/20] cpu/hotplug: Split out cpu down functions Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
[tip:smp/hotplug] cpu/hotplug: Split out cpu down functions tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
Re: [tip:smp/hotplug] cpu/hotplug: Split out cpu down functions "Srivatsa S. Bhat" <srivatsa@csail.mit.edu> - 2016-03-03 00:10 +0100
[patch 03/20] cpu/hotplug: Restructure cpu_up code Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
[tip:smp/hotplug] cpu/hotplug: Restructure cpu_up code tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
Re: [tip:smp/hotplug] cpu/hotplug: Restructure cpu_up code "Srivatsa S. Bhat" <srivatsa@csail.mit.edu> - 2016-03-03 00:00 +0100
[patch 16/20] cpu/hotplug: Move online calls to hotplugged cpu Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
[tip:smp/hotplug] cpu/hotplug: Move online calls to hotplugged cpu tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
[patch 02/20] cpu/hotplug: Restructure FROZEN state handling Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
[tip:smp/hotplug] cpu/hotplug: Restructure FROZEN state handling tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
Re: [tip:smp/hotplug] cpu/hotplug: Restructure FROZEN state handling "Srivatsa S. Bhat" <srivatsa@csail.mit.edu> - 2016-03-03 00:10 +0100
Re: [tip:smp/hotplug] cpu/hotplug: Restructure FROZEN state handling "Srivatsa S. Bhat" <srivatsa@csail.mit.edu> - 2016-03-03 00:50 +0100
[patch 11/20] cpu/hotplug: Implement setup/removal interface Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
[tip:smp/hotplug] cpu/hotplug: Implement setup/removal interface tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
[patch 12/20] cpu/hotplug: Move scheduler cpu_online notifier to hotplug core Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
[tip:smp/hotplug] cpu/hotplug: Move scheduler cpu_online notifier to hotplug core tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
[patch 18/20] cpu/hotplug: Let upcoming cpu bring itself fully up Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
[tip:smp/hotplug] cpu/hotplug: Let upcoming cpu bring itself fully up tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
Re: [patch 18/20] cpu/hotplug: Let upcoming cpu bring itself fully up Richard Cochran <richardcochran@gmail.com> - 2016-03-02 18:30 +0100
[patch 15/20] cpu/hotplug: Create hotplug threads Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
[tip:smp/hotplug] cpu/hotplug: Create hotplug threads tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
[patch 09/20] cpu/hotplug: Add sysfs state interface Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
[tip:smp/hotplug] cpu/hotplug: Add sysfs state interface tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
Re: [tip:smp/hotplug] cpu/hotplug: Add sysfs state interface Peter Zijlstra <peterz@infradead.org> - 2016-03-02 13:50 +0100
[patch 06/20] cpu/hotplug: Convert to a state machine for the control processor Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
[tip:smp/hotplug] cpu/hotplug: Convert to a state machine for the control processor tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
Re: [tip:smp/hotplug] cpu/hotplug: Convert to a state machine for the control processor Peter Zijlstra <peterz@infradead.org> - 2016-03-02 12:30 +0100
[patch 20/20] rcu: Make CPU_DYING_IDLE an explicit call Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
Re: [patch 20/20] rcu: Make CPU_DYING_IDLE an explicit call "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-02-27 03:20 +0100
Re: [patch 20/20] rcu: Make CPU_DYING_IDLE an explicit call "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-02-27 03:30 +0100
Re: [patch 20/20] rcu: Make CPU_DYING_IDLE an explicit call Thomas Gleixner <tglx@linutronix.de> - 2016-02-27 08:50 +0100
Re: [patch 20/20] rcu: Make CPU_DYING_IDLE an explicit call "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-02-27 12:10 +0100
Re: [patch 20/20] rcu: Make CPU_DYING_IDLE an explicit call Thomas Gleixner <tglx@linutronix.de> - 2016-02-27 12:40 +0100
Re: [patch 20/20] rcu: Make CPU_DYING_IDLE an explicit call "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-02-27 17:40 +0100
[tip:smp/hotplug] rcu: Make CPU_DYING_IDLE an explicit call tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
Re: [tip:smp/hotplug] rcu: Make CPU_DYING_IDLE an explicit call "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-03-02 21:20 +0100
Re: [tip:smp/hotplug] rcu: Make CPU_DYING_IDLE an explicit call Thomas Gleixner <tglx@linutronix.de> - 2016-03-03 08:40 +0100
[tip:smp/hotplug] cpu/hotplug: Plug death reporting race tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-03 11:10 +0100
Re: [tip:smp/hotplug] cpu/hotplug: Plug death reporting race "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-03-03 15:20 +0100
[patch 08/20] cpu/hotplug: Hand in target state to _cpu_up/down Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
[tip:smp/hotplug] cpu/hotplug: Hand in target state to _cpu_up/down tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
[patch 19/20] cpu/hotplug: Make wait for dead cpu completion based Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 19:50 +0100
[tip:smp/hotplug] cpu/hotplug: Make wait for dead cpu completion based tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
[patch 07/20] cpu/hotplug: Convert the hotplugged cpu work to a state machine Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 20:00 +0100
[tip:smp/hotplug] cpu/hotplug: Convert the hotplugged cpu work to a state machine tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-01 21:00 +0100
[patch 01/20] idle: Move x86ism out of generic code Thomas Gleixner <tglx@linutronix.de> - 2016-02-26 20:00 +0100
Re: [patch 01/20] idle: Move x86ism out of generic code Brian Gerst <brgerst@gmail.com> - 2016-02-27 21:30 +0100
Re: [patch 01/20] idle: Move x86ism out of generic code Thomas Gleixner <tglx@linutronix.de> - 2016-02-29 20:40 +0100
Re: [patch 01/20] idle: Move x86ism out of generic code Will Deacon <will.deacon@arm.com> - 2016-02-29 20:50 +0100
Re: [patch 01/20] idle: Move x86ism out of generic code Thomas Gleixner <tglx@linutronix.de> - 2016-02-29 21:10 +0100
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