[PATCH 12/40] workqueue: define both bit position and mask for work flags

Tejun Heo
2010-01-18T00:53:22Z

Work flags are about to see more traditional mask handling. Define
WORK_STRUCT_*_BIT as the bit position constant and redefine
WORK_STRUCT_* as bit masks.

While at it, re-define these constants as enums and use
WORK_STRUCT_STATIC instead of hard-coding 2 in
WORK_DATA_STATIC_INIT().

Signed-off-by: Tejun Heo <tj@kernel.org>
---
include/linux/workqueue.h | 23 +++++++++++++++--------
kernel/workqueue.c | 14 +++++++-------
2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 495572a..e51b5dc 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -22,12 +22,19 @@ typedef void (*work_func_t)(struct work_struct *work);
*/
#define work_data_bits(work) ((unsigned long *)(&(work)->data))

+enum {
+ WORK_STRUCT_PENDING_BIT = 0, /* work item is pending execution */
+ WORK_STRUCT_STATIC_BIT = 1, /* static initializer (debugobjects) */
+
+ WORK_STRUCT_PENDING = 1 << WORK_STRUCT_PENDING_BIT,
+ WORK_STRUCT_STATIC = 1 << WORK_STRUCT_STATIC_BIT,
+
+ WORK_STRUCT_FLAG_MASK = 3UL,
+ WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK,
+};
+
struct work_struct {
atomic_long_t data;
-#define WORK_STRUCT_PENDING 0 /* T if work item pending execution */
-#define WORK_STRUCT_STATIC 1 /* static initializer (debugobjects) */
-#define WORK_STRUCT_FLAG_MASK (3UL)
-#define WORK_STRUCT_WQ_DATA_MASK (~WORK_STRUCT_FLAG_MASK)
struct list_head entry;
work_func_t func;
#ifdef CONFIG_LOCKDEP
@@ -36,7 +43,7 @@ struct work_struct {
};

#define WORK_DATA_INIT() ATOMIC_LONG_INIT(0)
-#define WORK_DATA_STATIC_INIT() ATOMIC_LONG_INIT(2)
+#define WORK_DATA_STATIC_INIT() ATOMIC_LONG_INIT(WORK_STRUCT_STATIC)

struct delayed_work {
struct work_struct work;
@@ -98,7 +105,7 @@ extern void __init_work(struct work_struct *work, int onstack);
extern void destroy_work_on_stack(struct work_struct *work);
static inline bool work_static(struct work_struct *work)
{
- return test_bit(WORK_STRUCT_STATIC, work_data_bits(work));
+ return test_bit(WORK_STRUCT_STATIC_BIT, work_data_bits(work));
}
#else
static inline void __init_work(struct work_struct *work, int onstack) { }
@@ -167,7 +174,7 @@ static inline bool work_static(struct work_struct *work) { return false; }
* @work: The work item in question
*/
#define work_pending(work) \
- test_bit(WORK_STRUCT_PENDING, work_data_bits(work))
+ test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))

/**
* delayed_work_pending - Find out whether a delayable work item is currently
@@ -182,7 +189,7 @@ static inline bool work_static(struct work_struct *work) { return false; }
* @work: The work item in question
*/
#define work_clear_pending(work) \
- clear_bit(WORK_STRUCT_PENDING, work_data_bits(work))
+ clear_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))

enum {
WQ_FREEZEABLE = 1 << 0, /* freeze during suspend */
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 579041f..f8e4d67 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -115,7 +115,7 @@ static int work_fixup_activate(void *addr, enum debug_obj_state state)
* statically initialized. We just make sure that it
* is tracked in the object tracker.
*/
- if (test_bit(WORK_STRUCT_STATIC, work_data_bits(work))) {
+ if (test_bit(WORK_STRUCT_STATIC_BIT, work_data_bits(work))) {
debug_object_init(work, &work_debug_descr);
debug_object_activate(work, &work_debug_descr);
return 0;
@@ -232,8 +232,8 @@ static inline void set_wq_data(struct work_struct *work,
BUG_ON(!work_pending(work));

atomic_long_set(&work->data, (unsigned long)cwq |
- (work_static(work) ? (1UL << WORK_STRUCT_STATIC) : 0) |
- (1UL << WORK_STRUCT_PENDING) | extra_flags);
+ (work_static(work) ? WORK_STRUCT_STATIC : 0) |
+ WORK_STRUCT_PENDING | extra_flags);
}

static inline
@@ -323,7 +323,7 @@ queue_work_on(int cpu, struct workqueue_struct *wq, struct work_struct *work)
{
int ret = 0;

- if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) {
+ if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
__queue_work(cpu, wq, work);
ret = 1;
}
@@ -373,7 +373,7 @@ 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(WORK_STRUCT_PENDING, work_data_bits(work))) {
+ if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
BUG_ON(timer_pending(timer));
BUG_ON(!list_empty(&work->entry));

@@ -509,7 +509,7 @@ static void insert_wq_barrier(struct cpu_workqueue_struct *cwq,
* might deadlock.
*/
INIT_WORK_ON_STACK(&barr->work, wq_barrier_func);
- __set_bit(WORK_STRUCT_PENDING, work_data_bits(&barr->work));
+ __set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(&barr->work));
init_completion(&barr->done);

debug_work_activate(&barr->work);
@@ -621,7 +621,7 @@ static int try_to_grab_pending(struct work_struct *work)
struct cpu_workqueue_struct *cwq;
int ret = -1;

- if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work)))
+ if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work)))
return 0;

/*
--
1.6.4.2