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authorDavid Howells <dhowells@redhat.com>2006-11-22 09:54:49 -0500
committerDavid Howells <dhowells@redhat.com>2006-11-22 09:54:49 -0500
commit365970a1ea76d81cb1ad2f652acb605f06dae256 (patch)
treed2a34e397a4c2d9d0c27ceb0854752afe143c100
parent6bb49e5965c1fc399b4d3cd2b5cf2da535b330c0 (diff)
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: David Howells <dhowells@redhat.com>
-rw-r--r--drivers/block/floppy.c4
-rw-r--r--include/linux/workqueue.h27
-rw-r--r--kernel/workqueue.c41
3 files changed, 57 insertions, 15 deletions
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 5a14fac13b12..aa1eb4466f9d 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -1868,7 +1868,7 @@ static void show_floppy(void)
1868 printk("fdc_busy=%lu\n", fdc_busy); 1868 printk("fdc_busy=%lu\n", fdc_busy);
1869 if (do_floppy) 1869 if (do_floppy)
1870 printk("do_floppy=%p\n", do_floppy); 1870 printk("do_floppy=%p\n", do_floppy);
1871 if (floppy_work.pending) 1871 if (work_pending(&floppy_work))
1872 printk("floppy_work.func=%p\n", floppy_work.func); 1872 printk("floppy_work.func=%p\n", floppy_work.func);
1873 if (timer_pending(&fd_timer)) 1873 if (timer_pending(&fd_timer))
1874 printk("fd_timer.function=%p\n", fd_timer.function); 1874 printk("fd_timer.function=%p\n", fd_timer.function);
@@ -4498,7 +4498,7 @@ static void floppy_release_irq_and_dma(void)
4498 printk("floppy timer still active:%s\n", timeout_message); 4498 printk("floppy timer still active:%s\n", timeout_message);
4499 if (timer_pending(&fd_timer)) 4499 if (timer_pending(&fd_timer))
4500 printk("auxiliary floppy timer still active\n"); 4500 printk("auxiliary floppy timer still active\n");
4501 if (floppy_work.pending) 4501 if (work_pending(&floppy_work))
4502 printk("work still pending\n"); 4502 printk("work still pending\n");
4503#endif 4503#endif
4504 old_fdc = fdc; 4504 old_fdc = fdc;
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index cef40b22ff9a..ecc017d24cf3 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -14,11 +14,15 @@ struct workqueue_struct;
14typedef void (*work_func_t)(void *data); 14typedef void (*work_func_t)(void *data);
15 15
16struct work_struct { 16struct work_struct {
17 unsigned long pending; 17 /* the first word is the work queue pointer and the pending flag
18 * rolled into one */
19 unsigned long management;
20#define WORK_STRUCT_PENDING 0 /* T if work item pending execution */
21#define WORK_STRUCT_FLAG_MASK (3UL)
22#define WORK_STRUCT_WQ_DATA_MASK (~WORK_STRUCT_FLAG_MASK)
18 struct list_head entry; 23 struct list_head entry;
19 work_func_t func; 24 work_func_t func;
20 void *data; 25 void *data;
21 void *wq_data;
22}; 26};
23 27
24struct delayed_work { 28struct delayed_work {
@@ -65,7 +69,7 @@ struct execute_work {
65#define INIT_WORK(_work, _func, _data) \ 69#define INIT_WORK(_work, _func, _data) \
66 do { \ 70 do { \
67 INIT_LIST_HEAD(&(_work)->entry); \ 71 INIT_LIST_HEAD(&(_work)->entry); \
68 (_work)->pending = 0; \ 72 (_work)->management = 0; \
69 PREPARE_WORK((_work), (_func), (_data)); \ 73 PREPARE_WORK((_work), (_func), (_data)); \
70 } while (0) 74 } while (0)
71 75
@@ -75,6 +79,21 @@ struct execute_work {
75 init_timer(&(_work)->timer); \ 79 init_timer(&(_work)->timer); \
76 } while (0) 80 } while (0)
77 81
82/**
83 * work_pending - Find out whether a work item is currently pending
84 * @work: The work item in question
85 */
86#define work_pending(work) \
87 test_bit(WORK_STRUCT_PENDING, &(work)->management)
88
89/**
90 * delayed_work_pending - Find out whether a delayable work item is currently
91 * pending
92 * @work: The work item in question
93 */
94#define delayed_work_pending(work) \
95 test_bit(WORK_STRUCT_PENDING, &(work)->work.management)
96
78 97
79extern struct workqueue_struct *__create_workqueue(const char *name, 98extern struct workqueue_struct *__create_workqueue(const char *name,
80 int singlethread); 99 int singlethread);
@@ -115,7 +134,7 @@ static inline int cancel_delayed_work(struct delayed_work *work)
115 134
116 ret = del_timer_sync(&work->timer); 135 ret = del_timer_sync(&work->timer);
117 if (ret) 136 if (ret)
118 clear_bit(0, &work->work.pending); 137 clear_bit(WORK_STRUCT_PENDING, &work->work.management);
119 return ret; 138 return ret;
120} 139}
121 140
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 1e9d61ecf762..967479756511 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -80,6 +80,29 @@ static inline int is_single_threaded(struct workqueue_struct *wq)
80 return list_empty(&wq->list); 80 return list_empty(&wq->list);
81} 81}
82 82
83static inline void set_wq_data(struct work_struct *work, void *wq)
84{
85 unsigned long new, old, res;
86
87 /* assume the pending flag is already set and that the task has already
88 * been queued on this workqueue */
89 new = (unsigned long) wq | (1UL << WORK_STRUCT_PENDING);
90 res = work->management;
91 if (res != new) {
92 do {
93 old = res;
94 new = (unsigned long) wq;
95 new |= (old & WORK_STRUCT_FLAG_MASK);
96 res = cmpxchg(&work->management, old, new);
97 } while (res != old);
98 }
99}
100
101static inline void *get_wq_data(struct work_struct *work)
102{
103 return (void *) (work->management & WORK_STRUCT_WQ_DATA_MASK);
104}
105
83/* Preempt must be disabled. */ 106/* Preempt must be disabled. */
84static void __queue_work(struct cpu_workqueue_struct *cwq, 107static void __queue_work(struct cpu_workqueue_struct *cwq,
85 struct work_struct *work) 108 struct work_struct *work)
@@ -87,7 +110,7 @@ static void __queue_work(struct cpu_workqueue_struct *cwq,
87 unsigned long flags; 110 unsigned long flags;
88 111
89 spin_lock_irqsave(&cwq->lock, flags); 112 spin_lock_irqsave(&cwq->lock, flags);
90 work->wq_data = cwq; 113 set_wq_data(work, cwq);
91 list_add_tail(&work->entry, &cwq->worklist); 114 list_add_tail(&work->entry, &cwq->worklist);
92 cwq->insert_sequence++; 115 cwq->insert_sequence++;
93 wake_up(&cwq->more_work); 116 wake_up(&cwq->more_work);
@@ -108,7 +131,7 @@ int fastcall queue_work(struct workqueue_struct *wq, struct work_struct *work)
108{ 131{
109 int ret = 0, cpu = get_cpu(); 132 int ret = 0, cpu = get_cpu();
110 133
111 if (!test_and_set_bit(0, &work->pending)) { 134 if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) {
112 if (unlikely(is_single_threaded(wq))) 135 if (unlikely(is_single_threaded(wq)))
113 cpu = singlethread_cpu; 136 cpu = singlethread_cpu;
114 BUG_ON(!list_empty(&work->entry)); 137 BUG_ON(!list_empty(&work->entry));
@@ -123,7 +146,7 @@ EXPORT_SYMBOL_GPL(queue_work);
123static void delayed_work_timer_fn(unsigned long __data) 146static void delayed_work_timer_fn(unsigned long __data)
124{ 147{
125 struct delayed_work *dwork = (struct delayed_work *)__data; 148 struct delayed_work *dwork = (struct delayed_work *)__data;
126 struct workqueue_struct *wq = dwork->work.wq_data; 149 struct workqueue_struct *wq = get_wq_data(&dwork->work);
127 int cpu = smp_processor_id(); 150 int cpu = smp_processor_id();
128 151
129 if (unlikely(is_single_threaded(wq))) 152 if (unlikely(is_single_threaded(wq)))
@@ -150,12 +173,12 @@ int fastcall queue_delayed_work(struct workqueue_struct *wq,
150 if (delay == 0) 173 if (delay == 0)
151 return queue_work(wq, work); 174 return queue_work(wq, work);
152 175
153 if (!test_and_set_bit(0, &work->pending)) { 176 if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) {
154 BUG_ON(timer_pending(timer)); 177 BUG_ON(timer_pending(timer));
155 BUG_ON(!list_empty(&work->entry)); 178 BUG_ON(!list_empty(&work->entry));
156 179
157 /* This stores wq for the moment, for the timer_fn */ 180 /* This stores wq for the moment, for the timer_fn */
158 work->wq_data = wq; 181 set_wq_data(work, wq);
159 timer->expires = jiffies + delay; 182 timer->expires = jiffies + delay;
160 timer->data = (unsigned long)dwork; 183 timer->data = (unsigned long)dwork;
161 timer->function = delayed_work_timer_fn; 184 timer->function = delayed_work_timer_fn;
@@ -182,12 +205,12 @@ int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
182 struct timer_list *timer = &dwork->timer; 205 struct timer_list *timer = &dwork->timer;
183 struct work_struct *work = &dwork->work; 206 struct work_struct *work = &dwork->work;
184 207
185 if (!test_and_set_bit(0, &work->pending)) { 208 if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) {
186 BUG_ON(timer_pending(timer)); 209 BUG_ON(timer_pending(timer));
187 BUG_ON(!list_empty(&work->entry)); 210 BUG_ON(!list_empty(&work->entry));
188 211
189 /* This stores wq for the moment, for the timer_fn */ 212 /* This stores wq for the moment, for the timer_fn */
190 work->wq_data = wq; 213 set_wq_data(work, wq);
191 timer->expires = jiffies + delay; 214 timer->expires = jiffies + delay;
192 timer->data = (unsigned long)dwork; 215 timer->data = (unsigned long)dwork;
193 timer->function = delayed_work_timer_fn; 216 timer->function = delayed_work_timer_fn;
@@ -223,8 +246,8 @@ static void run_workqueue(struct cpu_workqueue_struct *cwq)
223 list_del_init(cwq->worklist.next); 246 list_del_init(cwq->worklist.next);
224 spin_unlock_irqrestore(&cwq->lock, flags); 247 spin_unlock_irqrestore(&cwq->lock, flags);
225 248
226 BUG_ON(work->wq_data != cwq); 249 BUG_ON(get_wq_data(work) != cwq);
227 clear_bit(0, &work->pending); 250 clear_bit(WORK_STRUCT_PENDING, &work->management);
228 f(data); 251 f(data);
229 252
230 spin_lock_irqsave(&cwq->lock, flags); 253 spin_lock_irqsave(&cwq->lock, flags);