Get rid of the prio ordering of the separate notifiers and use a
proper state callback pair.
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
---
include/linux/cpu.h | 8 ----
include/linux/cpuhotplug.h | 7 +++
kernel/cpu.c | 8 ++++
kernel/workqueue.c | 80 ++++++++++++++++-----------------------------
4 files changed, 44 insertions(+), 59 deletions(-)
Index: linux-2.6/include/linux/cpu.h
===================================================================
--- linux-2.6.orig/include/linux/cpu.h
+++ linux-2.6/include/linux/cpu.h
@@ -54,14 +54,6 @@ extern ssize_t arch_print_cpu_modalias(s
char *bufptr);
#endif
-/*
- * CPU notifier priorities.
- */
-enum {
- CPU_PRI_WORKQUEUE_UP = 5,
- CPU_PRI_WORKQUEUE_DOWN = -5,
-};
-
#define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
#define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
#define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up
*/
Index: linux-2.6/include/linux/cpuhotplug.h
===================================================================
--- linux-2.6.orig/include/linux/cpuhotplug.h
+++ linux-2.6/include/linux/cpuhotplug.h
@@ -11,6 +11,7 @@ enum cpuhp_states {
CPUHP_PERF_SUPERH,
CPUHP_PERF_PREPARE,
CPUHP_SCHED_MIGRATE_PREP,
+ CPUHP_WORKQUEUE_PREP,
CPUHP_NOTIFY_PREPARE,
CPUHP_NOTIFY_DEAD,
CPUHP_SCHED_DEAD,
@@ -29,6 +30,7 @@ enum cpuhp_states {
CPUHP_SCHED_ONLINE,
CPUHP_PERF_ONLINE,
CPUHP_SCHED_MIGRATE_ONLINE,
+ CPUHP_WORKQUEUE_ONLINE,
CPUHP_NOTIFY_ONLINE,
CPUHP_NOTIFY_DOWN_PREPARE,
CPUHP_PERF_X86_UNCORE_ONLINE,
@@ -127,4 +129,9 @@ int perf_event_exit_cpu(unsigned int cpu
#define perf_event_exit_cpu NULL
#endif
+/* Workqueue related hotplug events */
+int workqueue_prepare_cpu(unsigned int cpu);
+int workqueue_online_cpu(unsigned int cpu);
+int workqueue_offline_cpu(unsigned int cpu);
+
#endif
Index: linux-2.6/kernel/cpu.c
===================================================================
--- linux-2.6.orig/kernel/cpu.c
+++ linux-2.6/kernel/cpu.c
@@ -758,6 +758,10 @@ static struct cpuhp_step cpuhp_bp_states
.startup = sched_migration_prepare_cpu,
.teardown = sched_migration_dead_cpu,
},
+ [CPUHP_WORKQUEUE_PREP] = {
+ .startup = workqueue_prepare_cpu,
+ .teardown = NULL,
+ },
[CPUHP_NOTIFY_PREPARE] = {
.startup = notify_prepare,
.teardown = NULL,
@@ -786,6 +790,10 @@ static struct cpuhp_step cpuhp_bp_states
.startup = sched_migration_online_cpu,
.teardown = NULL,
},
+ [CPUHP_WORKQUEUE_ONLINE] = {
+ .startup = workqueue_online_cpu,
+ .teardown = workqueue_offline_cpu,
+ },
[CPUHP_NOTIFY_ONLINE] = {
.startup = notify_online,
.teardown = NULL,
Index: linux-2.6/kernel/workqueue.c
===================================================================
--- linux-2.6.orig/kernel/workqueue.c
+++ linux-2.6/kernel/workqueue.c
@@ -3588,67 +3588,48 @@ static void gcwq_unbind_fn(struct work_s
atomic_set(get_pool_nr_running(pool), 0);
}
-/*
- * Workqueues should be brought up before normal priority CPU notifiers.
- * This will be registered high priority CPU notifier.
- */
-static int __cpuinit workqueue_cpu_up_callback(struct notifier_block *nfb,
- unsigned long action,
- void *hcpu)
+int __cpuinit workqueue_prepare_cpu(unsigned int cpu)
{
- unsigned int cpu = (unsigned long)hcpu;
struct global_cwq *gcwq = get_gcwq(cpu);
struct worker_pool *pool;
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_UP_PREPARE:
- for_each_worker_pool(pool, gcwq) {
- struct worker *worker;
-
- if (pool->nr_workers)
- continue;
+ for_each_worker_pool(pool, gcwq) {
+ struct worker *worker;
- worker = create_worker(pool);
- if (!worker)
- return NOTIFY_BAD;
+ if (pool->nr_workers)
+ continue;
- spin_lock_irq(&gcwq->lock);
- start_worker(worker);
- spin_unlock_irq(&gcwq->lock);
- }
- break;
+ worker = create_worker(pool);
+ if (!worker)
+ return -ENOMEM;
- case CPU_DOWN_FAILED:
- case CPU_ONLINE:
- gcwq_claim_assoc_and_lock(gcwq);
- gcwq->flags &= ~GCWQ_DISASSOCIATED;
- rebind_workers(gcwq);
- gcwq_release_assoc_and_unlock(gcwq);
- break;
+ spin_lock_irq(&gcwq->lock);
+ start_worker(worker);
+ spin_unlock_irq(&gcwq->lock);
}
- return NOTIFY_OK;
+ return 0;
}
-/*
- * Workqueues should be brought down after normal priority CPU notifiers.
- * This will be registered as low priority CPU notifier.
- */
-static int __cpuinit workqueue_cpu_down_callback(struct notifier_block *nfb,
- unsigned long action,
- void *hcpu)
+int __cpuinit workqueue_online_cpu(unsigned int cpu)
+{
+ struct global_cwq *gcwq = get_gcwq(cpu);
+
+ gcwq_claim_assoc_and_lock(gcwq);
+ gcwq->flags &= ~GCWQ_DISASSOCIATED;
+ rebind_workers(gcwq);
+ gcwq_release_assoc_and_unlock(gcwq);
+ return 0;
+}
+
+int __cpuinit workqueue_offline_cpu(unsigned int cpu)
{
- unsigned int cpu = (unsigned long)hcpu;
struct work_struct unbind_work;
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_DOWN_PREPARE:
- /* unbinding should happen on the local CPU */
- INIT_WORK_ONSTACK(&unbind_work, gcwq_unbind_fn);
- queue_work_on(cpu, system_highpri_wq, &unbind_work);
- flush_work(&unbind_work);
- break;
- }
- return NOTIFY_OK;
+ /* unbinding should happen on the local CPU */
+ INIT_WORK_ONSTACK(&unbind_work, gcwq_unbind_fn);
+ queue_work_on(cpu, system_highpri_wq, &unbind_work);
+ flush_work(&unbind_work);
+ return 0;
}
#ifdef CONFIG_SMP
@@ -3837,9 +3818,6 @@ static int __init init_workqueues(void)
BUILD_BUG_ON((1LU << (BITS_PER_LONG - WORK_OFFQ_CPU_SHIFT)) <
WORK_CPU_LAST);
- cpu_notifier(workqueue_cpu_up_callback, CPU_PRI_WORKQUEUE_UP);
- hotcpu_notifier(workqueue_cpu_down_callback, CPU_PRI_WORKQUEUE_DOWN);
-
/* initialize gcwqs */
for_each_gcwq_cpu(cpu) {
struct global_cwq *gcwq = get_gcwq(cpu);
--
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