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cpu/hotplug: Unpark smpboot threads from the state machine 

Handle the smpboot threads in the state machine.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Rik van Riel <riel@redhat.com>
Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>
Cc: "Srivatsa S. Bhat" <srivatsa@mit.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: http://lkml.kernel.org/r/20160226182341.295777684@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner 2016-02-26 18:43:36 +00:00
parent 949338e351
commit 931ef16330
6 changed files with 13 additions and 45 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
include/linux/cpu.h
View File

@ -78,7 +78,7 @@ enum {
/* migration should happen before other stuff but after perf */
CPU_PRI_PERF = 20,
CPU_PRI_MIGRATION = 10,
CPU_PRI_SMPBOOT = 9,
/* bring up workqueues before normal notifiers and down after */
CPU_PRI_WORKQUEUE_UP = 5,
CPU_PRI_WORKQUEUE_DOWN = -5,
@ -172,7 +172,6 @@ static inline void __unregister_cpu_notifier(struct notifier_block *nb)
}
#endif
void smpboot_thread_init(void);
int cpu_up(unsigned int cpu);
void notify_cpu_starting(unsigned int cpu);
extern void cpu_maps_update_begin(void);
@ -221,10 +220,6 @@ static inline void cpu_notifier_register_done(void)
{
}
static inline void smpboot_thread_init(void)
{
}
#endif /* CONFIG_SMP */
extern struct bus_type cpu_subsys;

1
include/linux/cpuhotplug.h
View File

@ -11,6 +11,7 @@ enum cpuhp_state {
CPUHP_AP_ONLINE,
CPUHP_TEARDOWN_CPU,
CPUHP_CPU_SET_ACTIVE,
CPUHP_SMPBOOT_THREADS,
CPUHP_NOTIFY_ONLINE,
CPUHP_ONLINE_DYN,
CPUHP_ONLINE_DYN_END = CPUHP_ONLINE_DYN + 30,

1
init/main.c
View File

@ -388,7 +388,6 @@ static noinline void __init_refok rest_init(void)
int pid;
rcu_scheduler_starting();
smpboot_thread_init();
/*
* We need to spawn init first so that it obtains pid 1, however
* the init task will end up wanting to create kthreads, which, if

39
kernel/cpu.c
View File

@ -481,8 +481,6 @@ static int takedown_cpu(unsigned int cpu)
else
synchronize_rcu();
smpboot_park_threads(cpu);
/*
* Prevent irq alloc/free while the dying cpu reorganizes the
* interrupt affinities.
@ -612,38 +610,6 @@ int cpu_down(unsigned int cpu)
EXPORT_SYMBOL(cpu_down);
#endif /*CONFIG_HOTPLUG_CPU*/
/*
* Unpark per-CPU smpboot kthreads at CPU-online time.
*/
static int smpboot_thread_call(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
int cpu = (long)hcpu;
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_DOWN_FAILED:
case CPU_ONLINE:
smpboot_unpark_threads(cpu);
break;
default:
break;
}
return NOTIFY_OK;
}
static struct notifier_block smpboot_thread_notifier = {
.notifier_call = smpboot_thread_call,
.priority = CPU_PRI_SMPBOOT,
};
void smpboot_thread_init(void)
{
register_cpu_notifier(&smpboot_thread_notifier);
}
/**
* notify_cpu_starting(cpu) - call the CPU_STARTING notifiers
* @cpu: cpu that just started
@ -959,6 +925,11 @@ static struct cpuhp_step cpuhp_bp_states[] = {
.startup = cpuhp_set_cpu_active,
.teardown = NULL,
},
[CPUHP_SMPBOOT_THREADS] = {
.name = "smpboot:threads",
.startup = smpboot_unpark_threads,
.teardown = smpboot_park_threads,
},
[CPUHP_NOTIFY_ONLINE] = {
.name = "notify:online",
.startup = notify_online,

6
kernel/smpboot.c
View File

@ -226,7 +226,7 @@ static void smpboot_unpark_thread(struct smp_hotplug_thread *ht, unsigned int cp
kthread_unpark(tsk);
}
void smpboot_unpark_threads(unsigned int cpu)
int smpboot_unpark_threads(unsigned int cpu)
{
struct smp_hotplug_thread *cur;
@ -235,6 +235,7 @@ void smpboot_unpark_threads(unsigned int cpu)
if (cpumask_test_cpu(cpu, cur->cpumask))
smpboot_unpark_thread(cur, cpu);
mutex_unlock(&smpboot_threads_lock);
return 0;
}
static void smpboot_park_thread(struct smp_hotplug_thread *ht, unsigned int cpu)
@ -245,7 +246,7 @@ static void smpboot_park_thread(struct smp_hotplug_thread *ht, unsigned int cpu)
kthread_park(tsk);
}
void smpboot_park_threads(unsigned int cpu)
int smpboot_park_threads(unsigned int cpu)
{
struct smp_hotplug_thread *cur;
@ -253,6 +254,7 @@ void smpboot_park_threads(unsigned int cpu)
list_for_each_entry_reverse(cur, &hotplug_threads, list)
smpboot_park_thread(cur, cpu);
mutex_unlock(&smpboot_threads_lock);
return 0;
}
static void smpboot_destroy_threads(struct smp_hotplug_thread *ht)

4
kernel/smpboot.h
View File

@ -14,7 +14,7 @@ static inline void idle_threads_init(void) { }
#endif
int smpboot_create_threads(unsigned int cpu);
void smpboot_park_threads(unsigned int cpu);
void smpboot_unpark_threads(unsigned int cpu);
int smpboot_park_threads(unsigned int cpu);
int smpboot_unpark_threads(unsigned int cpu);
#endif