Commit-ID: 931ef163309ee955611f287dc65248b39a65fc9d
Gitweb: http://git.kernel.org/tip/931ef163309ee955611f287dc65248b39a65fc9d
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Fri, 26 Feb 2016 18:43:36 +0000
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 1 Mar 2016 20:36:56 +0100
cpu/hotplug: Unpark smpboot threads from the state machine
Handle the smpboot threads in the state machine.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Rafael Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: "Srivatsa S. Bhat" <srivatsa@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Cc: Sebastian Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Paul McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Paul Turner <pjt@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/20160226182341.295777684@xxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
include/linux/cpu.h | 7 +------
include/linux/cpuhotplug.h | 1 +
init/main.c | 1 -
kernel/cpu.c | 39 +++++----------------------------------
kernel/smpboot.c | 6 ++++--
kernel/smpboot.h | 4 ++--
6 files changed, 13 insertions(+), 45 deletions(-)
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 78989f2..83f3576 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -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;
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 2f2e5d9..3867910 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -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,
diff --git a/init/main.c b/init/main.c
index c2ea723..55563fd 100644
--- a/init/main.c
+++ b/init/main.c
@@ -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
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 65e34d3..3ec86bc 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -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,
diff --git a/kernel/smpboot.c b/kernel/smpboot.c
index d264f59..13bc43d 100644
--- a/kernel/smpboot.c
+++ b/kernel/smpboot.c
@@ -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)
diff --git a/kernel/smpboot.h b/kernel/smpboot.h
index 72415a0..6b5f020 100644
--- a/kernel/smpboot.h
+++ b/kernel/smpboot.h
@@ -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
--
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