diff options
| -rw-r--r-- | include/linux/workqueue.h | 11 | ||||
| -rw-r--r-- | kernel/workqueue.c | 108 |
2 files changed, 117 insertions, 2 deletions
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 48b7422f25ae..0a7f79729380 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -61,6 +61,10 @@ enum { WORK_STRUCT_FLAG_MASK = (1UL << WORK_STRUCT_FLAG_BITS) - 1, WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK, WORK_STRUCT_NO_CPU = NR_CPUS << WORK_STRUCT_FLAG_BITS, + + /* bit mask for work_busy() return values */ + WORK_BUSY_PENDING = 1 << 0, + WORK_BUSY_RUNNING = 1 << 1, }; struct work_struct { @@ -307,9 +311,14 @@ extern void init_workqueues(void); int execute_in_process_context(work_func_t fn, struct execute_work *); extern int flush_work(struct work_struct *work); - extern int cancel_work_sync(struct work_struct *work); +extern void workqueue_set_max_active(struct workqueue_struct *wq, + int max_active); +extern bool workqueue_congested(unsigned int cpu, struct workqueue_struct *wq); +extern unsigned int work_cpu(struct work_struct *work); +extern unsigned int work_busy(struct work_struct *work); + /* * Kill off a pending schedule_delayed_work(). Note that the work callback * function may still be running on return from cancel_delayed_work(), unless diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 16ce617974d2..c1aa65c2ff38 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -203,7 +203,7 @@ struct workqueue_struct { cpumask_var_t mayday_mask; /* cpus requesting rescue */ struct worker *rescuer; /* I: rescue worker */ - int saved_max_active; /* I: saved cwq max_active */ + int saved_max_active; /* W: saved cwq max_active */ const char *name; /* I: workqueue name */ #ifdef CONFIG_LOCKDEP struct lockdep_map lockdep_map; @@ -2675,6 +2675,112 @@ void destroy_workqueue(struct workqueue_struct *wq) } EXPORT_SYMBOL_GPL(destroy_workqueue); +/** + * workqueue_set_max_active - adjust max_active of a workqueue + * @wq: target workqueue + * @max_active: new max_active value. + * + * Set max_active of @wq to @max_active. + * + * CONTEXT: + * Don't call from IRQ context. + */ +void workqueue_set_max_active(struct workqueue_struct *wq, int max_active) +{ + unsigned int cpu; + + max_active = wq_clamp_max_active(max_active, wq->name); + + spin_lock(&workqueue_lock); + + wq->saved_max_active = max_active; + + for_each_possible_cpu(cpu) { + struct global_cwq *gcwq = get_gcwq(cpu); + + spin_lock_irq(&gcwq->lock); + + if (!(wq->flags & WQ_FREEZEABLE) || + !(gcwq->flags & GCWQ_FREEZING)) + get_cwq(gcwq->cpu, wq)->max_active = max_active; + + spin_unlock_irq(&gcwq->lock); + } + + spin_unlock(&workqueue_lock); +} +EXPORT_SYMBOL_GPL(workqueue_set_max_active); + +/** + * workqueue_congested - test whether a workqueue is congested + * @cpu: CPU in question + * @wq: target workqueue + * + * Test whether @wq's cpu workqueue for @cpu is congested. There is + * no synchronization around this function and the test result is + * unreliable and only useful as advisory hints or for debugging. + * + * RETURNS: + * %true if congested, %false otherwise. + */ +bool workqueue_congested(unsigned int cpu, struct workqueue_struct *wq) +{ + struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); + + return !list_empty(&cwq->delayed_works); +} +EXPORT_SYMBOL_GPL(workqueue_congested); + +/** + * work_cpu - return the last known associated cpu for @work + * @work: the work of interest + * + * RETURNS: + * CPU number if @work was ever queued. NR_CPUS otherwise. + */ +unsigned int work_cpu(struct work_struct *work) +{ + struct global_cwq *gcwq = get_work_gcwq(work); + + return gcwq ? gcwq->cpu : NR_CPUS; +} +EXPORT_SYMBOL_GPL(work_cpu); + +/** + * work_busy - test whether a work is currently pending or running + * @work: the work to be tested + * + * Test whether @work is currently pending or running. There is no + * synchronization around this function and the test result is + * unreliable and only useful as advisory hints or for debugging. + * Especially for reentrant wqs, the pending state might hide the + * running state. + * + * RETURNS: + * OR'd bitmask of WORK_BUSY_* bits. + */ +unsigned int work_busy(struct work_struct *work) +{ + struct global_cwq *gcwq = get_work_gcwq(work); + unsigned long flags; + unsigned int ret = 0; + + if (!gcwq) + return false; + + spin_lock_irqsave(&gcwq->lock, flags); + + if (work_pending(work)) + ret |= WORK_BUSY_PENDING; + if (find_worker_executing_work(gcwq, work)) + ret |= WORK_BUSY_RUNNING; + + spin_unlock_irqrestore(&gcwq->lock, flags); + + return ret; +} +EXPORT_SYMBOL_GPL(work_busy); + /* * CPU hotplug. * |