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authorLinus Torvalds <torvalds@linux-foundation.org>2013-09-06 09:36:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-09-06 09:36:28 -0700
commit2e515bf096c245ba87f20ab4b4ea20f911afaeda (patch)
tree8ce40f811092844ea9da683804db6e2afa410808 /kernel/workqueue.c
parent22e04f6b4b04a8afe9af9239224591d06ba3b24d (diff)
parentf8ea61e63442c25cbe6ddee48979b444f1f2a01c (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree from Jiri Kosina: "The usual trivial updates all over the tree -- mostly typo fixes and documentation updates" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (52 commits) doc: Documentation/cputopology.txt fix typo treewide: Convert retrun typos to return Fix comment typo for init_cma_reserved_pageblock Documentation/trace: Correcting and extending tracepoint documentation mm/hotplug: fix a typo in Documentation/memory-hotplug.txt power: Documentation: Update s2ram link doc: fix a typo in Documentation/00-INDEX Documentation/printk-formats.txt: No casts needed for u64/s64 doc: Fix typo "is is" in Documentations treewide: Fix printks with 0x%# zram: doc fixes Documentation/kmemcheck: update kmemcheck documentation doc: documentation/hwspinlock.txt fix typo PM / Hibernate: add section for resume options doc: filesystems : Fix typo in Documentations/filesystems scsi/megaraid fixed several typos in comments ppc: init_32: Fix error typo "CONFIG_START_KERNEL" treewide: Add __GFP_NOWARN to k.alloc calls with v.alloc fallbacks page_isolation: Fix a comment typo in test_pages_isolated() doc: fix a typo about irq affinity ...
Diffstat (limited to 'kernel/workqueue.c')
-rw-r--r--kernel/workqueue.c107
1 files changed, 66 insertions, 41 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 29b79852a845..987293d03ebc 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -541,6 +541,8 @@ static int worker_pool_assign_id(struct worker_pool *pool)
* This must be called either with pwq_lock held or sched RCU read locked.
* If the pwq needs to be used beyond the locking in effect, the caller is
* responsible for guaranteeing that the pwq stays online.
+ *
+ * Return: The unbound pool_workqueue for @node.
*/
static struct pool_workqueue *unbound_pwq_by_node(struct workqueue_struct *wq,
int node)
@@ -639,8 +641,6 @@ static struct pool_workqueue *get_work_pwq(struct work_struct *work)
* get_work_pool - return the worker_pool a given work was associated with
* @work: the work item of interest
*
- * Return the worker_pool @work was last associated with. %NULL if none.
- *
* Pools are created and destroyed under wq_pool_mutex, and allows read
* access under sched-RCU read lock. As such, this function should be
* called under wq_pool_mutex or with preemption disabled.
@@ -649,6 +649,8 @@ static struct pool_workqueue *get_work_pwq(struct work_struct *work)
* mentioned locking is in effect. If the returned pool needs to be used
* beyond the critical section, the caller is responsible for ensuring the
* returned pool is and stays online.
+ *
+ * Return: The worker_pool @work was last associated with. %NULL if none.
*/
static struct worker_pool *get_work_pool(struct work_struct *work)
{
@@ -672,7 +674,7 @@ static struct worker_pool *get_work_pool(struct work_struct *work)
* get_work_pool_id - return the worker pool ID a given work is associated with
* @work: the work item of interest
*
- * Return the worker_pool ID @work was last associated with.
+ * Return: The worker_pool ID @work was last associated with.
* %WORK_OFFQ_POOL_NONE if none.
*/
static int get_work_pool_id(struct work_struct *work)
@@ -831,7 +833,7 @@ void wq_worker_waking_up(struct task_struct *task, int cpu)
* CONTEXT:
* spin_lock_irq(rq->lock)
*
- * RETURNS:
+ * Return:
* Worker task on @cpu to wake up, %NULL if none.
*/
struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu)
@@ -966,8 +968,8 @@ static inline void worker_clr_flags(struct worker *worker, unsigned int flags)
* CONTEXT:
* spin_lock_irq(pool->lock).
*
- * RETURNS:
- * Pointer to worker which is executing @work if found, NULL
+ * Return:
+ * Pointer to worker which is executing @work if found, %NULL
* otherwise.
*/
static struct worker *find_worker_executing_work(struct worker_pool *pool,
@@ -1155,14 +1157,16 @@ out_put:
* @flags: place to store irq state
*
* Try to grab PENDING bit of @work. This function can handle @work in any
- * stable state - idle, on timer or on worklist. Return values are
+ * stable state - idle, on timer or on worklist.
*
+ * Return:
* 1 if @work was pending and we successfully stole PENDING
* 0 if @work was idle and we claimed PENDING
* -EAGAIN if PENDING couldn't be grabbed at the moment, safe to busy-retry
* -ENOENT if someone else is canceling @work, this state may persist
* for arbitrarily long
*
+ * Note:
* On >= 0 return, the caller owns @work's PENDING bit. To avoid getting
* interrupted while holding PENDING and @work off queue, irq must be
* disabled on entry. This, combined with delayed_work->timer being
@@ -1404,10 +1408,10 @@ retry:
* @wq: workqueue to use
* @work: work to queue
*
- * Returns %false if @work was already on a queue, %true otherwise.
- *
* We queue the work to a specific CPU, the caller must ensure it
* can't go away.
+ *
+ * Return: %false if @work was already on a queue, %true otherwise.
*/
bool queue_work_on(int cpu, struct workqueue_struct *wq,
struct work_struct *work)
@@ -1477,7 +1481,7 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq,
* @dwork: work to queue
* @delay: number of jiffies to wait before queueing
*
- * Returns %false if @work was already on a queue, %true otherwise. If
+ * Return: %false if @work was already on a queue, %true otherwise. If
* @delay is zero and @dwork is idle, it will be scheduled for immediate
* execution.
*/
@@ -1513,7 +1517,7 @@ EXPORT_SYMBOL(queue_delayed_work_on);
* zero, @work is guaranteed to be scheduled immediately regardless of its
* current state.
*
- * Returns %false if @dwork was idle and queued, %true if @dwork was
+ * Return: %false if @dwork was idle and queued, %true if @dwork was
* pending and its timer was modified.
*
* This function is safe to call from any context including IRQ handler.
@@ -1628,7 +1632,7 @@ static void worker_leave_idle(struct worker *worker)
* Might sleep. Called without any lock but returns with pool->lock
* held.
*
- * RETURNS:
+ * Return:
* %true if the associated pool is online (@worker is successfully
* bound), %false if offline.
*/
@@ -1689,7 +1693,7 @@ static struct worker *alloc_worker(void)
* CONTEXT:
* Might sleep. Does GFP_KERNEL allocations.
*
- * RETURNS:
+ * Return:
* Pointer to the newly created worker.
*/
static struct worker *create_worker(struct worker_pool *pool)
@@ -1789,6 +1793,8 @@ static void start_worker(struct worker *worker)
* @pool: the target pool
*
* Grab the managership of @pool and create and start a new worker for it.
+ *
+ * Return: 0 on success. A negative error code otherwise.
*/
static int create_and_start_worker(struct worker_pool *pool)
{
@@ -1933,7 +1939,7 @@ static void pool_mayday_timeout(unsigned long __pool)
* multiple times. Does GFP_KERNEL allocations. Called only from
* manager.
*
- * RETURNS:
+ * Return:
* %false if no action was taken and pool->lock stayed locked, %true
* otherwise.
*/
@@ -1990,7 +1996,7 @@ restart:
* spin_lock_irq(pool->lock) which may be released and regrabbed
* multiple times. Called only from manager.
*
- * RETURNS:
+ * Return:
* %false if no action was taken and pool->lock stayed locked, %true
* otherwise.
*/
@@ -2033,7 +2039,7 @@ static bool maybe_destroy_workers(struct worker_pool *pool)
* spin_lock_irq(pool->lock) which may be released and regrabbed
* multiple times. Does GFP_KERNEL allocations.
*
- * RETURNS:
+ * Return:
* %false if the pool don't need management and the caller can safely start
* processing works, %true indicates that the function released pool->lock
* and reacquired it to perform some management function and that the
@@ -2259,6 +2265,8 @@ static void process_scheduled_works(struct worker *worker)
* work items regardless of their specific target workqueue. The only
* exception is work items which belong to workqueues with a rescuer which
* will be explained in rescuer_thread().
+ *
+ * Return: 0
*/
static int worker_thread(void *__worker)
{
@@ -2357,6 +2365,8 @@ sleep:
* those works so that forward progress can be guaranteed.
*
* This should happen rarely.
+ *
+ * Return: 0
*/
static int rescuer_thread(void *__rescuer)
{
@@ -2529,7 +2539,7 @@ static void insert_wq_barrier(struct pool_workqueue *pwq,
* CONTEXT:
* mutex_lock(wq->mutex).
*
- * RETURNS:
+ * Return:
* %true if @flush_color >= 0 and there's something to flush. %false
* otherwise.
*/
@@ -2850,7 +2860,7 @@ static bool __flush_work(struct work_struct *work)
* Wait until @work has finished execution. @work is guaranteed to be idle
* on return if it hasn't been requeued since flush started.
*
- * RETURNS:
+ * Return:
* %true if flush_work() waited for the work to finish execution,
* %false if it was already idle.
*/
@@ -2902,7 +2912,7 @@ static bool __cancel_work_timer(struct work_struct *work, bool is_dwork)
* The caller must ensure that the workqueue on which @work was last
* queued can't be destroyed before this function returns.
*
- * RETURNS:
+ * Return:
* %true if @work was pending, %false otherwise.
*/
bool cancel_work_sync(struct work_struct *work)
@@ -2919,7 +2929,7 @@ EXPORT_SYMBOL_GPL(cancel_work_sync);
* immediate execution. Like flush_work(), this function only
* considers the last queueing instance of @dwork.
*
- * RETURNS:
+ * Return:
* %true if flush_work() waited for the work to finish execution,
* %false if it was already idle.
*/
@@ -2937,11 +2947,15 @@ EXPORT_SYMBOL(flush_delayed_work);
* cancel_delayed_work - cancel a delayed work
* @dwork: delayed_work to cancel
*
- * Kill off a pending delayed_work. Returns %true if @dwork was pending
- * and canceled; %false if wasn't pending. Note that the work callback
- * function may still be running on return, unless it returns %true and the
- * work doesn't re-arm itself. Explicitly flush or use
- * cancel_delayed_work_sync() to wait on it.
+ * Kill off a pending delayed_work.
+ *
+ * Return: %true if @dwork was pending and canceled; %false if it wasn't
+ * pending.
+ *
+ * Note:
+ * The work callback function may still be running on return, unless
+ * it returns %true and the work doesn't re-arm itself. Explicitly flush or
+ * use cancel_delayed_work_sync() to wait on it.
*
* This function is safe to call from any context including IRQ handler.
*/
@@ -2970,7 +2984,7 @@ EXPORT_SYMBOL(cancel_delayed_work);
*
* This is cancel_work_sync() for delayed works.
*
- * RETURNS:
+ * Return:
* %true if @dwork was pending, %false otherwise.
*/
bool cancel_delayed_work_sync(struct delayed_work *dwork)
@@ -2987,7 +3001,7 @@ EXPORT_SYMBOL(cancel_delayed_work_sync);
* system workqueue and blocks until all CPUs have completed.
* schedule_on_each_cpu() is very slow.
*
- * RETURNS:
+ * Return:
* 0 on success, -errno on failure.
*/
int schedule_on_each_cpu(work_func_t func)
@@ -3055,7 +3069,7 @@ EXPORT_SYMBOL(flush_scheduled_work);
* Executes the function immediately if process context is available,
* otherwise schedules the function for delayed execution.
*
- * Returns: 0 - function was executed
+ * Return: 0 - function was executed
* 1 - function was scheduled for execution
*/
int execute_in_process_context(work_func_t fn, struct execute_work *ew)
@@ -3315,7 +3329,7 @@ static void wq_device_release(struct device *dev)
* apply_workqueue_attrs() may race against userland updating the
* attributes.
*
- * Returns 0 on success, -errno on failure.
+ * Return: 0 on success, -errno on failure.
*/
int workqueue_sysfs_register(struct workqueue_struct *wq)
{
@@ -3408,7 +3422,9 @@ void free_workqueue_attrs(struct workqueue_attrs *attrs)
* @gfp_mask: allocation mask to use
*
* Allocate a new workqueue_attrs, initialize with default settings and
- * return it. Returns NULL on failure.
+ * return it.
+ *
+ * Return: The allocated new workqueue_attr on success. %NULL on failure.
*/
struct workqueue_attrs *alloc_workqueue_attrs(gfp_t gfp_mask)
{
@@ -3467,7 +3483,8 @@ static bool wqattrs_equal(const struct workqueue_attrs *a,
* @pool: worker_pool to initialize
*
* Initiailize a newly zalloc'd @pool. It also allocates @pool->attrs.
- * Returns 0 on success, -errno on failure. Even on failure, all fields
+ *
+ * Return: 0 on success, -errno on failure. Even on failure, all fields
* inside @pool proper are initialized and put_unbound_pool() can be called
* on @pool safely to release it.
*/
@@ -3574,9 +3591,12 @@ static void put_unbound_pool(struct worker_pool *pool)
* Obtain a worker_pool which has the same attributes as @attrs, bump the
* reference count and return it. If there already is a matching
* worker_pool, it will be used; otherwise, this function attempts to
- * create a new one. On failure, returns NULL.
+ * create a new one.
*
* Should be called with wq_pool_mutex held.
+ *
+ * Return: On success, a worker_pool with the same attributes as @attrs.
+ * On failure, %NULL.
*/
static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs)
{
@@ -3812,9 +3832,7 @@ static void free_unbound_pwq(struct pool_workqueue *pwq)
*
* Calculate the cpumask a workqueue with @attrs should use on @node. If
* @cpu_going_down is >= 0, that cpu is considered offline during
- * calculation. The result is stored in @cpumask. This function returns
- * %true if the resulting @cpumask is different from @attrs->cpumask,
- * %false if equal.
+ * calculation. The result is stored in @cpumask.
*
* If NUMA affinity is not enabled, @attrs->cpumask is always used. If
* enabled and @node has online CPUs requested by @attrs, the returned
@@ -3823,6 +3841,9 @@ static void free_unbound_pwq(struct pool_workqueue *pwq)
*
* The caller is responsible for ensuring that the cpumask of @node stays
* stable.
+ *
+ * Return: %true if the resulting @cpumask is different from @attrs->cpumask,
+ * %false if equal.
*/
static bool wq_calc_node_cpumask(const struct workqueue_attrs *attrs, int node,
int cpu_going_down, cpumask_t *cpumask)
@@ -3876,8 +3897,9 @@ static struct pool_workqueue *numa_pwq_tbl_install(struct workqueue_struct *wq,
* items finish. Note that a work item which repeatedly requeues itself
* back-to-back will stay on its current pwq.
*
- * Performs GFP_KERNEL allocations. Returns 0 on success and -errno on
- * failure.
+ * Performs GFP_KERNEL allocations.
+ *
+ * Return: 0 on success and -errno on failure.
*/
int apply_workqueue_attrs(struct workqueue_struct *wq,
const struct workqueue_attrs *attrs)
@@ -4345,6 +4367,8 @@ EXPORT_SYMBOL_GPL(workqueue_set_max_active);
*
* Determine whether %current is a workqueue rescuer. Can be used from
* work functions to determine whether it's being run off the rescuer task.
+ *
+ * Return: %true if %current is a workqueue rescuer. %false otherwise.
*/
bool current_is_workqueue_rescuer(void)
{
@@ -4368,7 +4392,7 @@ bool current_is_workqueue_rescuer(void)
* workqueue being congested on one CPU doesn't mean the workqueue is also
* contested on other CPUs / NUMA nodes.
*
- * RETURNS:
+ * Return:
* %true if congested, %false otherwise.
*/
bool workqueue_congested(int cpu, struct workqueue_struct *wq)
@@ -4401,7 +4425,7 @@ EXPORT_SYMBOL_GPL(workqueue_congested);
* synchronization around this function and the test result is
* unreliable and only useful as advisory hints or for debugging.
*
- * RETURNS:
+ * Return:
* OR'd bitmask of WORK_BUSY_* bits.
*/
unsigned int work_busy(struct work_struct *work)
@@ -4779,9 +4803,10 @@ static void work_for_cpu_fn(struct work_struct *work)
* @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.
* The caller must not hold any locks which would prevent @fn from completing.
+ *
+ * Return: The value @fn returns.
*/
long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
{
@@ -4853,7 +4878,7 @@ void freeze_workqueues_begin(void)
* CONTEXT:
* Grabs and releases wq_pool_mutex.
*
- * RETURNS:
+ * Return:
* %true if some freezable workqueues are still busy. %false if freezing
* is complete.
*/