[PATCH 26/35] workqueue: implement worker_{set|clr}_flags()

From: Tejun Heo
Date: Mon Jun 28 2010 - 17:13:19 EST


Implement worker_{set|clr}_flags() to manipulate worker flags. These
are currently simple wrappers but logics to track the current worker
state and the current level of concurrency will be added.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
kernel/workqueue.c | 48 ++++++++++++++++++++++++++++++++++++++++--------
1 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index e0a7609..8b90d87 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -412,6 +412,38 @@ static void wake_up_worker(struct global_cwq *gcwq)
}

/**
+ * worker_set_flags - set worker flags
+ * @worker: worker to set flags for
+ * @flags: flags to set
+ * @wakeup: wakeup an idle worker if necessary
+ *
+ * Set @flags in @worker->flags.
+ *
+ * LOCKING:
+ * spin_lock_irq(gcwq->lock).
+ */
+static inline void worker_set_flags(struct worker *worker, unsigned int flags,
+ bool wakeup)
+{
+ worker->flags |= flags;
+}
+
+/**
+ * worker_clr_flags - clear worker flags
+ * @worker: worker to set flags for
+ * @flags: flags to clear
+ *
+ * Clear @flags in @worker->flags.
+ *
+ * LOCKING:
+ * spin_lock_irq(gcwq->lock).
+ */
+static inline void worker_clr_flags(struct worker *worker, unsigned int flags)
+{
+ worker->flags &= ~flags;
+}
+
+/**
* busy_worker_head - return the busy hash head for a work
* @gcwq: gcwq of interest
* @work: work to be hashed
@@ -776,7 +808,7 @@ static void worker_enter_idle(struct worker *worker)
BUG_ON(!list_empty(&worker->entry) &&
(worker->hentry.next || worker->hentry.pprev));

- worker->flags |= WORKER_IDLE;
+ worker_set_flags(worker, WORKER_IDLE, false);
gcwq->nr_idle++;

/* idle_list is LIFO */
@@ -800,7 +832,7 @@ static void worker_leave_idle(struct worker *worker)
struct global_cwq *gcwq = worker->gcwq;

BUG_ON(!(worker->flags & WORKER_IDLE));
- worker->flags &= ~WORKER_IDLE;
+ worker_clr_flags(worker, WORKER_IDLE);
gcwq->nr_idle--;
list_del_init(&worker->entry);
}
@@ -890,7 +922,7 @@ fail:
*/
static void start_worker(struct worker *worker)
{
- worker->flags |= WORKER_STARTED;
+ worker_set_flags(worker, WORKER_STARTED, false);
worker->gcwq->nr_workers++;
worker_enter_idle(worker);
wake_up_process(worker->task);
@@ -920,7 +952,7 @@ static void destroy_worker(struct worker *worker)
gcwq->nr_idle--;

list_del_init(&worker->entry);
- worker->flags |= WORKER_DIE;
+ worker_set_flags(worker, WORKER_DIE, false);

spin_unlock_irq(&gcwq->lock);

@@ -2208,10 +2240,10 @@ static int __cpuinit trustee_thread(void *__gcwq)
BUG_ON(gcwq->cpu != smp_processor_id());

list_for_each_entry(worker, &gcwq->idle_list, entry)
- worker->flags |= WORKER_ROGUE;
+ worker_set_flags(worker, WORKER_ROGUE, false);

for_each_busy_worker(worker, i, pos, gcwq)
- worker->flags |= WORKER_ROGUE;
+ worker_set_flags(worker, WORKER_ROGUE, false);

/*
* We're now in charge. Notify and proceed to drain. We need
@@ -2318,10 +2350,10 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,

/* clear ROGUE from all workers */
list_for_each_entry(worker, &gcwq->idle_list, entry)
- worker->flags &= ~WORKER_ROGUE;
+ worker_clr_flags(worker, WORKER_ROGUE);

for_each_busy_worker(worker, i, pos, gcwq)
- worker->flags &= ~WORKER_ROGUE;
+ worker_clr_flags(worker, WORKER_ROGUE);
break;
}

--
1.6.4.2

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