Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 365970a1 authored by David Howells's avatar David Howells
Browse files

WorkStruct: Merge the pending bit into the wq_data pointer 



Reclaim a word from the size of the work_struct by folding the pending bit and
the wq_data pointer together.  This shouldn't cause misalignment problems as
all pointers should be at least 4-byte aligned.

Signed-Off-By: default avatarDavid Howells <dhowells@redhat.com>
parent 6bb49e59

drivers/block/floppy.c

+2 −2
Original line number Diff line number Diff line
@@ -1868,7 +1868,7 @@ static void show_floppy(void) 
	printk("fdc_busy=%lu\n", fdc_busy);

	if (do_floppy)

		printk("do_floppy=%p\n", do_floppy);

	if (floppy_work.pending)

	if (work_pending(&floppy_work))

		printk("floppy_work.func=%p\n", floppy_work.func);

	if (timer_pending(&fd_timer))

		printk("fd_timer.function=%p\n", fd_timer.function);
@@ -4498,7 +4498,7 @@ static void floppy_release_irq_and_dma(void) 
		printk("floppy timer still active:%s\n", timeout_message);

	if (timer_pending(&fd_timer))

		printk("auxiliary floppy timer still active\n");

	if (floppy_work.pending)

	if (work_pending(&floppy_work))

		printk("work still pending\n");

#endif

	old_fdc = fdc;

include/linux/workqueue.h

+23 −4
Original line number Diff line number Diff line
@@ -14,11 +14,15 @@ struct workqueue_struct; 
typedef void (*work_func_t)(void *data);



struct work_struct {

	unsigned long pending;

	/* the first word is the work queue pointer and the pending flag

	 * rolled into one */

	unsigned long management;

#define WORK_STRUCT_PENDING 0		/* T if work item pending execution */

#define WORK_STRUCT_FLAG_MASK (3UL)

#define WORK_STRUCT_WQ_DATA_MASK (~WORK_STRUCT_FLAG_MASK)

	struct list_head entry;

	work_func_t func;

	void *data;

	void *wq_data;

};



struct delayed_work {
@@ -65,7 +69,7 @@ struct execute_work { 
#define INIT_WORK(_work, _func, _data)				\

	do {							\

		INIT_LIST_HEAD(&(_work)->entry);		\

		(_work)->pending = 0;				\

		(_work)->management = 0;			\

		PREPARE_WORK((_work), (_func), (_data));	\

	} while (0)
@@ -75,6 +79,21 @@ struct execute_work { 
		init_timer(&(_work)->timer);			\

	} while (0)



/**

 * work_pending - Find out whether a work item is currently pending

 * @work: The work item in question

 */

#define work_pending(work) \

	test_bit(WORK_STRUCT_PENDING, &(work)->management)



/**

 * delayed_work_pending - Find out whether a delayable work item is currently

 * pending

 * @work: The work item in question

 */

#define delayed_work_pending(work) \

	test_bit(WORK_STRUCT_PENDING, &(work)->work.management)





extern struct workqueue_struct *__create_workqueue(const char *name,

						    int singlethread);
@@ -115,7 +134,7 @@ static inline int cancel_delayed_work(struct delayed_work *work) 


	ret = del_timer_sync(&work->timer);

	if (ret)

		clear_bit(0, &work->work.pending);

		clear_bit(WORK_STRUCT_PENDING, &work->work.management);

	return ret;

}

kernel/workqueue.c

+32 −9
Original line number Diff line number Diff line
@@ -80,6 +80,29 @@ static inline int is_single_threaded(struct workqueue_struct *wq) 
	return list_empty(&wq->list);

}



static inline void set_wq_data(struct work_struct *work, void *wq)

{

	unsigned long new, old, res;



	/* assume the pending flag is already set and that the task has already

	 * been queued on this workqueue */

	new = (unsigned long) wq | (1UL << WORK_STRUCT_PENDING);

	res = work->management;

	if (res != new) {

		do {

			old = res;

			new = (unsigned long) wq;

			new |= (old & WORK_STRUCT_FLAG_MASK);

			res = cmpxchg(&work->management, old, new);

		} while (res != old);

	}

}



static inline void *get_wq_data(struct work_struct *work)

{

	return (void *) (work->management & WORK_STRUCT_WQ_DATA_MASK);

}



/* Preempt must be disabled. */

static void __queue_work(struct cpu_workqueue_struct *cwq,

			 struct work_struct *work)
@@ -87,7 +110,7 @@ static void __queue_work(struct cpu_workqueue_struct *cwq, 
	unsigned long flags;



	spin_lock_irqsave(&cwq->lock, flags);

	work->wq_data = cwq;

	set_wq_data(work, cwq);

	list_add_tail(&work->entry, &cwq->worklist);

	cwq->insert_sequence++;

	wake_up(&cwq->more_work);
@@ -108,7 +131,7 @@ int fastcall queue_work(struct workqueue_struct *wq, struct work_struct *work) 
{

	int ret = 0, cpu = get_cpu();



	if (!test_and_set_bit(0, &work->pending)) {

	if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) {

		if (unlikely(is_single_threaded(wq)))

			cpu = singlethread_cpu;

		BUG_ON(!list_empty(&work->entry));
@@ -123,7 +146,7 @@ EXPORT_SYMBOL_GPL(queue_work); 
static void delayed_work_timer_fn(unsigned long __data)

{

	struct delayed_work *dwork = (struct delayed_work *)__data;

	struct workqueue_struct *wq = dwork->work.wq_data;

	struct workqueue_struct *wq = get_wq_data(&dwork->work);

	int cpu = smp_processor_id();



	if (unlikely(is_single_threaded(wq)))
@@ -150,12 +173,12 @@ int fastcall queue_delayed_work(struct workqueue_struct *wq, 
	if (delay == 0)

		return queue_work(wq, work);



	if (!test_and_set_bit(0, &work->pending)) {

	if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) {

		BUG_ON(timer_pending(timer));

		BUG_ON(!list_empty(&work->entry));



		/* This stores wq for the moment, for the timer_fn */

		work->wq_data = wq;

		set_wq_data(work, wq);

		timer->expires = jiffies + delay;

		timer->data = (unsigned long)dwork;

		timer->function = delayed_work_timer_fn;
@@ -182,12 +205,12 @@ int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, 
	struct timer_list *timer = &dwork->timer;

	struct work_struct *work = &dwork->work;



	if (!test_and_set_bit(0, &work->pending)) {

	if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) {

		BUG_ON(timer_pending(timer));

		BUG_ON(!list_empty(&work->entry));



		/* This stores wq for the moment, for the timer_fn */

		work->wq_data = wq;

		set_wq_data(work, wq);

		timer->expires = jiffies + delay;

		timer->data = (unsigned long)dwork;

		timer->function = delayed_work_timer_fn;
@@ -223,8 +246,8 @@ static void run_workqueue(struct cpu_workqueue_struct *cwq) 
		list_del_init(cwq->worklist.next);

		spin_unlock_irqrestore(&cwq->lock, flags);



		BUG_ON(work->wq_data != cwq);

		clear_bit(0, &work->pending);

		BUG_ON(get_wq_data(work) != cwq);

		clear_bit(WORK_STRUCT_PENDING, &work->management);

		f(data);



		spin_lock_irqsave(&cwq->lock, flags);