[PATCH v8 07/12] kthread: Add kthread_destroy_worker()

From: Petr Mladek
Date: Thu Jun 09 2016 - 09:52:37 EST


The current kthread worker users call flush() and stop() explicitly.
This function drains the worker, stops it, and frees the kthread_worker
struct in one call.

It is supposed to be used together with kthread_create_worker*() that
allocates struct kthread_worker.

Also note that drain() correctly handles self-queuing works in compare
with flush().

Signed-off-by: Petr Mladek <pmladek@xxxxxxxx>
---
include/linux/kthread.h | 2 ++
kernel/kthread.c | 21 +++++++++++++++++++++
2 files changed, 23 insertions(+)

diff --git a/include/linux/kthread.h b/include/linux/kthread.h
index 6fc0940b9657..c0a527581d95 100644
--- a/include/linux/kthread.h
+++ b/include/linux/kthread.h
@@ -137,4 +137,6 @@ void kthread_flush_work(struct kthread_work *work);
void kthread_flush_worker(struct kthread_worker *worker);
void kthread_drain_worker(struct kthread_worker *worker);

+void kthread_destroy_worker(struct kthread_worker *worker);
+
#endif /* _LINUX_KTHREAD_H */
diff --git a/kernel/kthread.c b/kernel/kthread.c
index fa3c327be889..d9f59fdcf466 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -853,3 +853,24 @@ void kthread_drain_worker(struct kthread_worker *worker)
spin_unlock_irq(&worker->lock);
}
EXPORT_SYMBOL(kthread_drain_worker);
+
+/**
+ * kthread_destroy_worker - destroy a kthread worker
+ * @worker: worker to be destroyed
+ *
+ * Drain and destroy @worker. It has the same conditions
+ * for use as kthread_drain_worker(), see above.
+ */
+void kthread_destroy_worker(struct kthread_worker *worker)
+{
+ struct task_struct *task;
+
+ task = worker->task;
+ if (WARN_ON(!task))
+ return;
+
+ kthread_drain_worker(worker);
+ kthread_stop(task);
+ kfree(worker);
+}
+EXPORT_SYMBOL(kthread_destroy_worker);
--
1.8.5.6