workqueue: introduce workqueue_struct->singlethread

Add explicit workqueue_struct->singlethread flag.  This lessens .text a
little, but most importantly this allows us to manipulate wq->list without
changine the meaning of is_single_threaded().

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2007-05-09 02:34:13 -07:00 committed by Linus Torvalds
parent b1f4ec172f
commit cce1a1656c

View File

@ -58,8 +58,9 @@ struct cpu_workqueue_struct {
*/
struct workqueue_struct {
struct cpu_workqueue_struct *cpu_wq;
struct list_head list;
const char *name;
struct list_head list; /* Empty if single thread */
int singlethread;
int freezeable; /* Freeze threads during suspend */
};
@ -76,7 +77,7 @@ static cpumask_t cpu_populated_map __read_mostly;
/* If it's single threaded, it isn't in the list of workqueues. */
static inline int is_single_threaded(struct workqueue_struct *wq)
{
return list_empty(&wq->list);
return wq->singlethread;
}
static const cpumask_t *wq_cpu_map(struct workqueue_struct *wq)
@ -401,7 +402,7 @@ static void flush_cpu_workqueue(struct cpu_workqueue_struct *cwq)
void fastcall flush_workqueue(struct workqueue_struct *wq)
{
const cpumask_t *cpu_map = wq_cpu_map(wq);
int cpu
int cpu;
might_sleep();
for_each_cpu_mask(cpu, *cpu_map)
@ -694,10 +695,11 @@ struct workqueue_struct *__create_workqueue(const char *name,
}
wq->name = name;
wq->singlethread = singlethread;
wq->freezeable = freezeable;
INIT_LIST_HEAD(&wq->list);
if (singlethread) {
INIT_LIST_HEAD(&wq->list);
cwq = init_cpu_workqueue(wq, singlethread_cpu);
err = create_workqueue_thread(cwq, singlethread_cpu);
} else {