dect
/
linux-2.6
Archived
13
0
Fork 0
Code Releases Activity

connector: remove lazy workqueue creation 

Commit 1a5645bc (connector: create connector workqueue only while
needed once) implements lazy workqueue creation for connector
workqueue.  With cmwq now in place, lazy workqueue creation doesn't
make much sense while adding a lot of complexity.  Remove it and
allocate an ordered workqueue during initialization.

This also removes a call to flush_scheduled_work() which is deprecated
and scheduled to be removed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tejun Heo 2010-10-14 23:55:22 +00:00 committed by David S. Miller
parent 229aebb873
commit 6cebb17bee
3 changed files with 12 additions and 80 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

75
drivers/connector/cn_queue.c
View File

@ -31,48 +31,6 @@
#include <linux/connector.h>
#include <linux/delay.h>
/*
* This job is sent to the kevent workqueue.
* While no event is once sent to any callback, the connector workqueue
* is not created to avoid a useless waiting kernel task.
* Once the first event is received, we create this dedicated workqueue which
* is necessary because the flow of data can be high and we don't want
* to encumber keventd with that.
*/
static void cn_queue_create(struct work_struct *work)
{
struct cn_queue_dev *dev;
dev = container_of(work, struct cn_queue_dev, wq_creation);
dev->cn_queue = create_singlethread_workqueue(dev->name);
/* If we fail, we will use keventd for all following connector jobs */
WARN_ON(!dev->cn_queue);
}
/*
* Queue a data sent to a callback.
* If the connector workqueue is already created, we queue the job on it.
* Otherwise, we queue the job to kevent and queue the connector workqueue
* creation too.
*/
int queue_cn_work(struct cn_callback_entry *cbq, struct work_struct *work)
{
struct cn_queue_dev *pdev = cbq->pdev;
if (likely(pdev->cn_queue))
return queue_work(pdev->cn_queue, work);
/* Don't create the connector workqueue twice */
if (atomic_inc_return(&pdev->wq_requested) == 1)
schedule_work(&pdev->wq_creation);
else
atomic_dec(&pdev->wq_requested);
return schedule_work(work);
}
void cn_queue_wrapper(struct work_struct *work)
{
struct cn_callback_entry *cbq =
@ -111,11 +69,7 @@ cn_queue_alloc_callback_entry(char *name, struct cb_id *id,
static void cn_queue_free_callback(struct cn_callback_entry *cbq)
{
/* The first jobs have been sent to kevent, flush them too */
flush_scheduled_work();
if (cbq->pdev->cn_queue)
flush_workqueue(cbq->pdev->cn_queue);
flush_workqueue(cbq->pdev->cn_queue);
kfree(cbq);
}
@ -193,11 +147,14 @@ struct cn_queue_dev *cn_queue_alloc_dev(char *name, struct sock *nls)
atomic_set(&dev->refcnt, 0);
INIT_LIST_HEAD(&dev->queue_list);
spin_lock_init(&dev->queue_lock);
init_waitqueue_head(&dev->wq_created);
dev->nls = nls;
INIT_WORK(&dev->wq_creation, cn_queue_create);
dev->cn_queue = alloc_ordered_workqueue(dev->name, 0);
if (!dev->cn_queue) {
kfree(dev);
return NULL;
}
return dev;
}
@ -205,25 +162,9 @@ struct cn_queue_dev *cn_queue_alloc_dev(char *name, struct sock *nls)
void cn_queue_free_dev(struct cn_queue_dev *dev)
{
struct cn_callback_entry *cbq, *n;
long timeout;
DEFINE_WAIT(wait);
/* Flush the first pending jobs queued on kevent */
flush_scheduled_work();
/* If the connector workqueue creation is still pending, wait for it */
prepare_to_wait(&dev->wq_created, &wait, TASK_UNINTERRUPTIBLE);
if (atomic_read(&dev->wq_requested) && !dev->cn_queue) {
timeout = schedule_timeout(HZ * 2);
if (!timeout && !dev->cn_queue)
WARN_ON(1);
}
finish_wait(&dev->wq_created, &wait);
if (dev->cn_queue) {
flush_workqueue(dev->cn_queue);
destroy_workqueue(dev->cn_queue);
}
flush_workqueue(dev->cn_queue);
destroy_workqueue(dev->cn_queue);
spin_lock_bh(&dev->queue_lock);
list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry)

9
drivers/connector/connector.c
View File

@ -133,7 +133,8 @@ static int cn_call_callback(struct sk_buff *skb)
__cbq->data.skb == NULL)) {
__cbq->data.skb = skb;
if (queue_cn_work(__cbq, &__cbq->work))
if (queue_work(dev->cbdev->cn_queue,
&__cbq->work))
err = 0;
else
err = -EINVAL;
@ -148,13 +149,11 @@ static int cn_call_callback(struct sk_buff *skb)
d->callback = __cbq->data.callback;
d->free = __new_cbq;
__new_cbq->pdev = __cbq->pdev;
INIT_WORK(&__new_cbq->work,
&cn_queue_wrapper);
if (queue_cn_work(__new_cbq,
&__new_cbq->work))
if (queue_work(dev->cbdev->cn_queue,
&__new_cbq->work))
err = 0;
else {
kfree(__new_cbq);

8
include/linux/connector.h
View File

@ -88,12 +88,6 @@ 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;
@ -141,8 +135,6 @@ 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)(struct cn_msg *, struct netlink_skb_parms *));
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);