X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fworkqueue.c;h=1f0c509b40d34d944bea77e300e237ab9145439c;hb=2d29c6a075787f2c1bc49b86a084d2b878f72fc4;hp=f12ab5c4dec4aa464cd11dfcb13c18a840c89f33;hpb=6cc88bc45ce8043171089c9592da223dfab91823;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index f12ab5c..1f0c509 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -73,7 +73,7 @@ static DEFINE_SPINLOCK(workqueue_lock);
 static LIST_HEAD(workqueues);
 
 static int singlethread_cpu __read_mostly;
-static cpumask_t cpu_singlethread_map __read_mostly;
+static const struct cpumask *cpu_singlethread_map __read_mostly;
 /*
  * _cpu_down() first removes CPU from cpu_online_map, then CPU_DEAD
  * flushes cwq->worklist. This means that flush_workqueue/wait_on_work
@@ -81,7 +81,7 @@ static cpumask_t cpu_singlethread_map __read_mostly;
  * use cpu_possible_map, the cpumask below is more a documentation
  * than optimization.
  */
-static cpumask_t cpu_populated_map __read_mostly;
+static cpumask_var_t cpu_populated_map __read_mostly;
 
 /* If it's single threaded, it isn't in the list of workqueues. */
 static inline int is_wq_single_threaded(struct workqueue_struct *wq)
@@ -89,10 +89,10 @@ static inline int is_wq_single_threaded(struct workqueue_struct *wq)
 	return wq->singlethread;
 }
 
-static const cpumask_t *wq_cpu_map(struct workqueue_struct *wq)
+static const struct cpumask *wq_cpu_map(struct workqueue_struct *wq)
 {
 	return is_wq_single_threaded(wq)
-		? &cpu_singlethread_map : &cpu_populated_map;
+		? cpu_singlethread_map : cpu_populated_map;
 }
 
 static
@@ -410,7 +410,7 @@ static int flush_cpu_workqueue(struct cpu_workqueue_struct *cwq)
  */
 void flush_workqueue(struct workqueue_struct *wq)
 {
-	const cpumask_t *cpu_map = wq_cpu_map(wq);
+	const struct cpumask *cpu_map = wq_cpu_map(wq);
 	int cpu;
 
 	might_sleep();
@@ -532,7 +532,7 @@ static void wait_on_work(struct work_struct *work)
 {
 	struct cpu_workqueue_struct *cwq;
 	struct workqueue_struct *wq;
-	const cpumask_t *cpu_map;
+	const struct cpumask *cpu_map;
 	int cpu;
 
 	might_sleep();
@@ -903,7 +903,7 @@ static void cleanup_workqueue_thread(struct cpu_workqueue_struct *cwq)
  */
 void destroy_workqueue(struct workqueue_struct *wq)
 {
-	const cpumask_t *cpu_map = wq_cpu_map(wq);
+	const struct cpumask *cpu_map = wq_cpu_map(wq);
 	int cpu;
 
 	cpu_maps_update_begin();
@@ -933,7 +933,7 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,
 
 	switch (action) {
 	case CPU_UP_PREPARE:
-		cpu_set(cpu, cpu_populated_map);
+		cpumask_set_cpu(cpu, cpu_populated_map);
 	}
 undo:
 	list_for_each_entry(wq, &workqueues, list) {
@@ -964,18 +964,65 @@ undo:
 	switch (action) {
 	case CPU_UP_CANCELED:
 	case CPU_POST_DEAD:
-		cpu_clear(cpu, cpu_populated_map);
+		cpumask_clear_cpu(cpu, cpu_populated_map);
 	}
 
 	return ret;
 }
 
+#ifdef CONFIG_SMP
+static struct workqueue_struct *work_on_cpu_wq __read_mostly;
+
+struct work_for_cpu {
+	struct work_struct work;
+	long (*fn)(void *);
+	void *arg;
+	long ret;
+};
+
+static void do_work_for_cpu(struct work_struct *w)
+{
+	struct work_for_cpu *wfc = container_of(w, struct work_for_cpu, work);
+
+	wfc->ret = wfc->fn(wfc->arg);
+}
+
+/**
+ * work_on_cpu - run a function in user context on a particular cpu
+ * @cpu: the cpu to run on
+ * @fn: the function to run
+ * @arg: the function arg
+ *
+ * This will return the value @fn returns.
+ * It is up to the caller to ensure that the cpu doesn't go offline.
+ */
+long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
+{
+	struct work_for_cpu wfc;
+
+	INIT_WORK(&wfc.work, do_work_for_cpu);
+	wfc.fn = fn;
+	wfc.arg = arg;
+	queue_work_on(cpu, work_on_cpu_wq, &wfc.work);
+	flush_work(&wfc.work);
+
+	return wfc.ret;
+}
+EXPORT_SYMBOL_GPL(work_on_cpu);
+#endif /* CONFIG_SMP */
+
 void __init init_workqueues(void)
 {
-	cpu_populated_map = cpu_online_map;
-	singlethread_cpu = first_cpu(cpu_possible_map);
-	cpu_singlethread_map = cpumask_of_cpu(singlethread_cpu);
+	alloc_cpumask_var(&cpu_populated_map, GFP_KERNEL);
+
+	cpumask_copy(cpu_populated_map, cpu_online_mask);
+	singlethread_cpu = cpumask_first(cpu_possible_mask);
+	cpu_singlethread_map = cpumask_of(singlethread_cpu);
 	hotcpu_notifier(workqueue_cpu_callback, 0);
 	keventd_wq = create_workqueue("events");
 	BUG_ON(!keventd_wq);
+#ifdef CONFIG_SMP
+	work_on_cpu_wq = create_workqueue("work_on_cpu");
+	BUG_ON(!work_on_cpu_wq);
+#endif
 }