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-rw-r--r--kernel/workqueue.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index e72fb6478da6..82c4fa70595c 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -29,7 +29,8 @@
29#include <linux/kthread.h> 29#include <linux/kthread.h>
30 30
31/* 31/*
32 * The per-CPU workqueue (if single thread, we always use cpu 0's). 32 * The per-CPU workqueue (if single thread, we always use the first
33 * possible cpu).
33 * 34 *
34 * The sequence counters are for flush_scheduled_work(). It wants to wait 35 * The sequence counters are for flush_scheduled_work(). It wants to wait
35 * until until all currently-scheduled works are completed, but it doesn't 36 * until until all currently-scheduled works are completed, but it doesn't
@@ -69,6 +70,8 @@ struct workqueue_struct {
69static DEFINE_SPINLOCK(workqueue_lock); 70static DEFINE_SPINLOCK(workqueue_lock);
70static LIST_HEAD(workqueues); 71static LIST_HEAD(workqueues);
71 72
73static int singlethread_cpu;
74
72/* If it's single threaded, it isn't in the list of workqueues. */ 75/* If it's single threaded, it isn't in the list of workqueues. */
73static inline int is_single_threaded(struct workqueue_struct *wq) 76static inline int is_single_threaded(struct workqueue_struct *wq)
74{ 77{
@@ -102,7 +105,7 @@ int fastcall queue_work(struct workqueue_struct *wq, struct work_struct *work)
102 105
103 if (!test_and_set_bit(0, &work->pending)) { 106 if (!test_and_set_bit(0, &work->pending)) {
104 if (unlikely(is_single_threaded(wq))) 107 if (unlikely(is_single_threaded(wq)))
105 cpu = any_online_cpu(cpu_online_map); 108 cpu = singlethread_cpu;
106 BUG_ON(!list_empty(&work->entry)); 109 BUG_ON(!list_empty(&work->entry));
107 __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work); 110 __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work);
108 ret = 1; 111 ret = 1;
@@ -118,7 +121,7 @@ static void delayed_work_timer_fn(unsigned long __data)
118 int cpu = smp_processor_id(); 121 int cpu = smp_processor_id();
119 122
120 if (unlikely(is_single_threaded(wq))) 123 if (unlikely(is_single_threaded(wq)))
121 cpu = any_online_cpu(cpu_online_map); 124 cpu = singlethread_cpu;
122 125
123 __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work); 126 __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work);
124} 127}
@@ -267,7 +270,7 @@ void fastcall flush_workqueue(struct workqueue_struct *wq)
267 270
268 if (is_single_threaded(wq)) { 271 if (is_single_threaded(wq)) {
269 /* Always use first cpu's area. */ 272 /* Always use first cpu's area. */
270 flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, any_online_cpu(cpu_online_map))); 273 flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, singlethread_cpu));
271 } else { 274 } else {
272 int cpu; 275 int cpu;
273 276
@@ -325,7 +328,7 @@ struct workqueue_struct *__create_workqueue(const char *name,
325 lock_cpu_hotplug(); 328 lock_cpu_hotplug();
326 if (singlethread) { 329 if (singlethread) {
327 INIT_LIST_HEAD(&wq->list); 330 INIT_LIST_HEAD(&wq->list);
328 p = create_workqueue_thread(wq, any_online_cpu(cpu_online_map)); 331 p = create_workqueue_thread(wq, singlethread_cpu);
329 if (!p) 332 if (!p)
330 destroy = 1; 333 destroy = 1;
331 else 334 else
@@ -379,7 +382,7 @@ void destroy_workqueue(struct workqueue_struct *wq)
379 /* We don't need the distraction of CPUs appearing and vanishing. */ 382 /* We don't need the distraction of CPUs appearing and vanishing. */
380 lock_cpu_hotplug(); 383 lock_cpu_hotplug();
381 if (is_single_threaded(wq)) 384 if (is_single_threaded(wq))
382 cleanup_workqueue_thread(wq, any_online_cpu(cpu_online_map)); 385 cleanup_workqueue_thread(wq, singlethread_cpu);
383 else { 386 else {
384 for_each_online_cpu(cpu) 387 for_each_online_cpu(cpu)
385 cleanup_workqueue_thread(wq, cpu); 388 cleanup_workqueue_thread(wq, cpu);
@@ -567,6 +570,7 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,
567 570
568void init_workqueues(void) 571void init_workqueues(void)
569{ 572{
573 singlethread_cpu = first_cpu(cpu_possible_map);
570 hotcpu_notifier(workqueue_cpu_callback, 0); 574 hotcpu_notifier(workqueue_cpu_callback, 0);
571 keventd_wq = create_workqueue("events"); 575 keventd_wq = create_workqueue("events");
572 BUG_ON(!keventd_wq); 576 BUG_ON(!keventd_wq);