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-rw-r--r--kernel/workqueue.c39
1 files changed, 37 insertions, 2 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 9953d3c7bd1..e541b5db67d 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -77,6 +77,9 @@ struct cpu_workqueue_struct {
int flush_color; /* L: flushing color */
int nr_in_flight[WORK_NR_COLORS];
/* L: nr of in_flight works */
+ int nr_active; /* L: nr of active works */
+ int max_active; /* I: max active works */
+ struct list_head delayed_works; /* L: delayed works */
};
/*
@@ -321,14 +324,24 @@ static void __queue_work(unsigned int cpu, struct workqueue_struct *wq,
struct work_struct *work)
{
struct cpu_workqueue_struct *cwq = target_cwq(cpu, wq);
+ struct list_head *worklist;
unsigned long flags;
debug_work_activate(work);
+
spin_lock_irqsave(&cwq->lock, flags);
BUG_ON(!list_empty(&work->entry));
+
cwq->nr_in_flight[cwq->work_color]++;
- insert_work(cwq, work, &cwq->worklist,
- work_color_to_flags(cwq->work_color));
+
+ if (likely(cwq->nr_active < cwq->max_active)) {
+ cwq->nr_active++;
+ worklist = &cwq->worklist;
+ } else
+ worklist = &cwq->delayed_works;
+
+ insert_work(cwq, work, worklist, work_color_to_flags(cwq->work_color));
+
spin_unlock_irqrestore(&cwq->lock, flags);
}
@@ -584,6 +597,15 @@ static void move_linked_works(struct work_struct *work, struct list_head *head,
*nextp = n;
}
+static void cwq_activate_first_delayed(struct cpu_workqueue_struct *cwq)
+{
+ struct work_struct *work = list_first_entry(&cwq->delayed_works,
+ struct work_struct, entry);
+
+ move_linked_works(work, &cwq->worklist, NULL);
+ cwq->nr_active++;
+}
+
/**
* cwq_dec_nr_in_flight - decrement cwq's nr_in_flight
* @cwq: cwq of interest
@@ -602,6 +624,12 @@ static void cwq_dec_nr_in_flight(struct cpu_workqueue_struct *cwq, int color)
return;
cwq->nr_in_flight[color]--;
+ cwq->nr_active--;
+
+ /* one down, submit a delayed one */
+ if (!list_empty(&cwq->delayed_works) &&
+ cwq->nr_active < cwq->max_active)
+ cwq_activate_first_delayed(cwq);
/* is flush in progress and are we at the flushing tip? */
if (likely(cwq->flush_color != color))
@@ -1505,6 +1533,7 @@ static void free_cwqs(struct cpu_workqueue_struct *cwqs)
struct workqueue_struct *__create_workqueue_key(const char *name,
unsigned int flags,
+ int max_active,
struct lock_class_key *key,
const char *lock_name)
{
@@ -1513,6 +1542,8 @@ struct workqueue_struct *__create_workqueue_key(const char *name,
bool failed = false;
unsigned int cpu;
+ max_active = clamp_val(max_active, 1, INT_MAX);
+
wq = kzalloc(sizeof(*wq), GFP_KERNEL);
if (!wq)
goto err;
@@ -1544,8 +1575,10 @@ struct workqueue_struct *__create_workqueue_key(const char *name,
cwq->cpu = cpu;
cwq->wq = wq;
cwq->flush_color = -1;
+ cwq->max_active = max_active;
spin_lock_init(&cwq->lock);
INIT_LIST_HEAD(&cwq->worklist);
+ INIT_LIST_HEAD(&cwq->delayed_works);
init_waitqueue_head(&cwq->more_work);
if (failed)
@@ -1607,6 +1640,8 @@ void destroy_workqueue(struct workqueue_struct *wq)
for (i = 0; i < WORK_NR_COLORS; i++)
BUG_ON(cwq->nr_in_flight[i]);
+ BUG_ON(cwq->nr_active);
+ BUG_ON(!list_empty(&cwq->delayed_works));
}
free_cwqs(wq->cpu_wq);