It's not clear why the ordering needs to be this way, but for the time
being we just keep the current working state. Want's to be revisited.
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
---
include/linux/cpu.h | 2
include/linux/cpuhotplug.h | 12 +++++
kernel/cpu.c | 12 +++++
kernel/sched/core.c | 103 +++++++++++++++++++--------------------------
4 files changed, 68 insertions(+), 61 deletions(-)
Index: linux-2.6/include/linux/cpu.h
===================================================================
--- linux-2.6.orig/include/linux/cpu.h
+++ linux-2.6/include/linux/cpu.h
@@ -58,8 +58,6 @@ extern ssize_t arch_print_cpu_modalias(s
* CPU notifier priorities.
*/
enum {
- CPU_PRI_MIGRATION = 10,
- /* bring up workqueues before normal notifiers and down after */
CPU_PRI_WORKQUEUE_UP = 5,
CPU_PRI_WORKQUEUE_DOWN = -5,
};
Index: linux-2.6/include/linux/cpuhotplug.h
===================================================================
--- linux-2.6.orig/include/linux/cpuhotplug.h
+++ linux-2.6/include/linux/cpuhotplug.h
@@ -10,6 +10,7 @@ enum cpuhp_states {
CPUHP_PERF_POWER,
CPUHP_PERF_SUPERH,
CPUHP_PERF_PREPARE,
+ CPUHP_SCHED_MIGRATE_PREP,
CPUHP_NOTIFY_PREPARE,
CPUHP_NOTIFY_DEAD,
CPUHP_SCHED_DEAD,
@@ -21,11 +22,13 @@ enum cpuhp_states {
CPUHP_AP_PERF_X86_STARTING,
CPUHP_AP_NOTIFY_STARTING,
CPUHP_AP_NOTIFY_DYING,
+ CPUHP_AP_SCHED_MIGRATE_DYING,
CPUHP_AP_MAX,
CPUHP_TEARDOWN_CPU,
CPUHP_PERCPU_THREADS,
CPUHP_SCHED_ONLINE,
CPUHP_PERF_ONLINE,
+ CPUHP_SCHED_MIGRATE_ONLINE,
CPUHP_NOTIFY_ONLINE,
CPUHP_NOTIFY_DOWN_PREPARE,
CPUHP_PERF_X86_UNCORE_ONLINE,
@@ -105,6 +108,15 @@ static inline void cpuhp_remove_state_no
/* Compiled in scheduler hotplug functions */
int sched_starting_cpu(unsigned int cpu);
+int sched_migration_prepare_cpu(unsigned int cpu);
+int sched_migration_online_cpu(unsigned int cpu);
+#ifdef CONFIG_HOTPLUG_CPU
+int sched_migration_dying_cpu(unsigned int cpu);
+int sched_migration_dead_cpu(unsigned int cpu);
+#else
+#define sched_migration_dying_cpu NULL
+#define sched_migration_dead_cpu NULL
+#endif
/* Performance counter hotplug functions */
#ifdef CONFIG_PERF_EVENTS
Index: linux-2.6/kernel/cpu.c
===================================================================
--- linux-2.6.orig/kernel/cpu.c
+++ linux-2.6/kernel/cpu.c
@@ -754,6 +754,10 @@ static struct cpuhp_step cpuhp_bp_states
.startup = perf_event_init_cpu,
.teardown = perf_event_exit_cpu,
},
+ [CPUHP_SCHED_MIGRATE_PREP] = {
+ .startup = sched_migration_prepare_cpu,
+ .teardown = sched_migration_dead_cpu,
+ },
[CPUHP_NOTIFY_PREPARE] = {
.startup = notify_prepare,
.teardown = NULL,
@@ -778,6 +782,10 @@ static struct cpuhp_step cpuhp_bp_states
.startup = perf_event_init_cpu,
.teardown = perf_event_exit_cpu,
},
+ [CPUHP_SCHED_MIGRATE_ONLINE] = {
+ .startup = sched_migration_online_cpu,
+ .teardown = NULL,
+ },
[CPUHP_NOTIFY_ONLINE] = {
.startup = notify_online,
.teardown = NULL,
@@ -808,6 +816,10 @@ static struct cpuhp_step cpuhp_ap_states
.startup = NULL,
.teardown = notify_dying,
},
+ [CPUHP_AP_SCHED_MIGRATE_DYING] = {
+ .startup = NULL,
+ .teardown = sched_migration_dying_cpu,
+ },
#endif
[CPUHP_MAX] = {
.startup = NULL,
Index: linux-2.6/kernel/sched/core.c
===================================================================
--- linux-2.6.orig/kernel/sched/core.c
+++ linux-2.6/kernel/sched/core.c
@@ -5104,80 +5104,65 @@ static void set_rq_offline(struct rq *rq
}
}
-/*
- * migration_call - callback that gets triggered when a CPU is added.
- * Here we can start up the necessary migration thread for the new CPU.
- */
-static int __cpuinit
-migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
+int __cpuinit sched_migration_prepare_cpu(unsigned int cpu)
{
- int cpu = (long)hcpu;
- unsigned long flags;
struct rq *rq = cpu_rq(cpu);
- switch (action & ~CPU_TASKS_FROZEN) {
-
- case CPU_UP_PREPARE:
- rq->calc_load_update = calc_load_update;
- break;
+ rq->calc_load_update = calc_load_update;
+ update_max_interval();
+ return 0;
+}
- case CPU_ONLINE:
- /* Update our root-domain */
- raw_spin_lock_irqsave(&rq->lock, flags);
- if (rq->rd) {
- BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
+int __cpuinit sched_migration_online_cpu(unsigned int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+ unsigned long flags;
- set_rq_online(rq);
- }
- raw_spin_unlock_irqrestore(&rq->lock, flags);
- break;
+ /* Update our root-domain */
+ raw_spin_lock_irqsave(&rq->lock, flags);
+ if (rq->rd) {
+ BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
+ set_rq_online(rq);
+ }
+ raw_spin_unlock_irqrestore(&rq->lock, flags);
+ update_max_interval();
+ return 0;
+}
#ifdef CONFIG_HOTPLUG_CPU
- case CPU_DYING:
- sched_ttwu_pending();
- /* Update our root-domain */
- raw_spin_lock_irqsave(&rq->lock, flags);
- if (rq->rd) {
- BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
- set_rq_offline(rq);
- }
- migrate_tasks(cpu);
- BUG_ON(rq->nr_running != 1); /* the migration thread */
- raw_spin_unlock_irqrestore(&rq->lock, flags);
- break;
+int __cpuinit sched_migration_dying_cpu(unsigned int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+ unsigned long flags;
- case CPU_DEAD:
- calc_load_migrate(rq);
- break;
-#endif
+ sched_ttwu_pending();
+ /* Update our root-domain */
+ raw_spin_lock_irqsave(&rq->lock, flags);
+ if (rq->rd) {
+ BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
+ set_rq_offline(rq);
}
-
+ migrate_tasks(cpu);
+ BUG_ON(rq->nr_running != 1); /* the migration thread */
+ raw_spin_unlock_irqrestore(&rq->lock, flags);
update_max_interval();
-
- return NOTIFY_OK;
+ return 0;
}
-/*
- * Register at high priority so that task migration (migrate_all_tasks)
- * happens before everything else. This has to be lower priority than
- * the notifier in the perf_event subsystem, though.
- */
-static struct notifier_block __cpuinitdata migration_notifier = {
- .notifier_call = migration_call,
- .priority = CPU_PRI_MIGRATION,
-};
-
-static int __init migration_init(void)
+int __cpuinit sched_migration_dead_cpu(unsigned int cpu)
{
- void *cpu = (void *)(long)smp_processor_id();
- int err;
+ struct rq *rq = cpu_rq(cpu);
- /* Initialize migration for the boot CPU */
- err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu);
- BUG_ON(err == NOTIFY_BAD);
- migration_call(&migration_notifier, CPU_ONLINE, cpu);
- register_cpu_notifier(&migration_notifier);
+ calc_load_migrate(rq);
+ update_max_interval();
+ return 0;
+}
+#endif
+static int __init migration_init(void)
+{
+ sched_migration_prepare_cpu(smp_processor_id());
+ sched_migration_online_cpu(smp_processor_id());
return 0;
}
early_initcall(migration_init);
--
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