From 1a5645bc901aea6f3f446888061b2b084bbf1ba6 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 2 Feb 2009 23:22:04 -0800 Subject: connector: create connector workqueue only while needed once The netlink connector uses its own workqueue to relay the datas sent from userspace to the appropriate callback. If you launch the test from Documentation/connector and change it a bit to send a high flow of data, you will see thousands of events coming to the "cqueue" workqueue by looking at the workqueue tracer. This flow of events can be sent very quickly. So, to not encumber the kevent workqueue and delay other jobs, the "cqueue" workqueue should remain. But this workqueue is pointless most of the time, it will always be created (assuming you have built it of course) although only developpers with specific needs will use it. So avoid this "most of the time useless task", this patch proposes to create this workqueue only when needed once. The first jobs to be sent to connector callbacks will be sent to kevent while the "cqueue" thread creation will be scheduled to kevent too. The following jobs will continue to be scheduled to keventd until the cqueue workqueue is created, and then the rest of the jobs will continue to perform as usual, through this dedicated workqueue. Each time I tested this patch, only the first event was sent to keventd, the rest has been sent to cqueue which have been created quickly. Also, this patch fixes some trailing whitespaces on the connector files. Signed-off-by: Frederic Weisbecker Acked-by: Evgeniy Polyakov Signed-off-by: David S. Miller --- include/linux/connector.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include') diff --git a/include/linux/connector.h b/include/linux/connector.h index 34f2789d9b9..fc65d219d88 100644 --- a/include/linux/connector.h +++ b/include/linux/connector.h @@ -109,6 +109,12 @@ struct cn_queue_dev { unsigned char name[CN_CBQ_NAMELEN]; struct workqueue_struct *cn_queue; + /* Sent to kevent to create cn_queue only when needed */ + struct work_struct wq_creation; + /* Tell if the wq_creation job is pending/completed */ + atomic_t wq_requested; + /* Wait for cn_queue to be created */ + wait_queue_head_t wq_created; struct list_head queue_list; spinlock_t queue_lock; @@ -164,6 +170,8 @@ int cn_netlink_send(struct cn_msg *, u32, gfp_t); int cn_queue_add_callback(struct cn_queue_dev *dev, char *name, struct cb_id *id, void (*callback)(void *)); void cn_queue_del_callback(struct cn_queue_dev *dev, struct cb_id *id); +int queue_cn_work(struct cn_callback_entry *cbq, struct work_struct *work); + struct cn_queue_dev *cn_queue_alloc_dev(char *name, struct sock *); void cn_queue_free_dev(struct cn_queue_dev *dev); -- cgit v1.2.3