vhost: Make it more scalable by creating a vhost thread per device.

Commit Message

Sridhar Samudrala April 2, 2010, 5:31 p.m. UTC

None

Patch

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index a6a88df..29aa80f 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -339,8 +339,10 @@  static int vhost_net_open(struct inode *inode, struct file *f)
 		return r;
 	}
 
-	vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT);
-	vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN);
+	vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT,
+			&n->dev);
+	vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN,
+			&n->dev);
 	n->tx_poll_state = VHOST_NET_POLL_DISABLED;
 
 	f->private_data = n;
@@ -643,25 +645,14 @@  static struct miscdevice vhost_net_misc = {
 
 int vhost_net_init(void)
 {
-	int r = vhost_init();
-	if (r)
-		goto err_init;
-	r = misc_register(&vhost_net_misc);
-	if (r)
-		goto err_reg;
-	return 0;
-err_reg:
-	vhost_cleanup();
-err_init:
-	return r;
-
+	return misc_register(&vhost_net_misc);
 }
+
 module_init(vhost_net_init);
 
 void vhost_net_exit(void)
 {
 	misc_deregister(&vhost_net_misc);
-	vhost_cleanup();
 }
 module_exit(vhost_net_exit);
 
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 7bd7a1e..243f4d3 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -36,8 +36,6 @@  enum {
 	VHOST_MEMORY_F_LOG = 0x1,
 };
 
-static struct workqueue_struct *vhost_workqueue;
-
 static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh,
 			    poll_table *pt)
 {
@@ -56,18 +54,19 @@  static int vhost_poll_wakeup(wait_queue_t *wait, unsigned mode, int sync,
 	if (!((unsigned long)key & poll->mask))
 		return 0;
 
-	queue_work(vhost_workqueue, &poll->work);
+	queue_work(poll->dev->wq, &poll->work);
 	return 0;
 }
 
 /* Init poll structure */
 void vhost_poll_init(struct vhost_poll *poll, work_func_t func,
-		     unsigned long mask)
+		     unsigned long mask, struct vhost_dev *dev)
 {
 	INIT_WORK(&poll->work, func);
 	init_waitqueue_func_entry(&poll->wait, vhost_poll_wakeup);
 	init_poll_funcptr(&poll->table, vhost_poll_func);
 	poll->mask = mask;
+	poll->dev = dev;
 }
 
 /* Start polling a file. We add ourselves to file's wait queue. The caller must
@@ -96,7 +95,7 @@  void vhost_poll_flush(struct vhost_poll *poll)
 
 void vhost_poll_queue(struct vhost_poll *poll)
 {
-	queue_work(vhost_workqueue, &poll->work);
+	queue_work(poll->dev->wq, &poll->work);
 }
 
 static void vhost_vq_reset(struct vhost_dev *dev,
@@ -128,6 +127,11 @@  long vhost_dev_init(struct vhost_dev *dev,
 		    struct vhost_virtqueue *vqs, int nvqs)
 {
 	int i;
+
+	dev->wq = create_singlethread_workqueue("vhost");
+	if (!dev->wq)
+		return -ENOMEM;
+
 	dev->vqs = vqs;
 	dev->nvqs = nvqs;
 	mutex_init(&dev->mutex);
@@ -143,7 +147,7 @@  long vhost_dev_init(struct vhost_dev *dev,
 		if (dev->vqs[i].handle_kick)
 			vhost_poll_init(&dev->vqs[i].poll,
 					dev->vqs[i].handle_kick,
-					POLLIN);
+					POLLIN, dev);
 	}
 	return 0;
 }
@@ -216,6 +220,8 @@  void vhost_dev_cleanup(struct vhost_dev *dev)
 	if (dev->mm)
 		mmput(dev->mm);
 	dev->mm = NULL;
+
+	destroy_workqueue(dev->wq);
 }
 
 static int log_access_ok(void __user *log_base, u64 addr, unsigned long sz)
@@ -1095,16 +1101,3 @@  void vhost_disable_notify(struct vhost_virtqueue *vq)
 		vq_err(vq, "Failed to enable notification at %p: %d\n",
 		       &vq->used->flags, r);
 }
-
-int vhost_init(void)
-{
-	vhost_workqueue = create_singlethread_workqueue("vhost");
-	if (!vhost_workqueue)
-		return -ENOMEM;
-	return 0;
-}
-
-void vhost_cleanup(void)
-{
-	destroy_workqueue(vhost_workqueue);
-}
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 44591ba..60fefd0 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -29,10 +29,11 @@  struct vhost_poll {
 	/* struct which will handle all actual work. */
 	struct work_struct        work;
 	unsigned long		  mask;
+	struct vhost_dev	 *dev;
 };
 
 void vhost_poll_init(struct vhost_poll *poll, work_func_t func,
-		     unsigned long mask);
+		     unsigned long mask, struct vhost_dev *dev);
 void vhost_poll_start(struct vhost_poll *poll, struct file *file);
 void vhost_poll_stop(struct vhost_poll *poll);
 void vhost_poll_flush(struct vhost_poll *poll);
@@ -110,6 +111,7 @@  struct vhost_dev {
 	int nvqs;
 	struct file *log_file;
 	struct eventfd_ctx *log_ctx;
+	struct workqueue_struct *wq;
 };
 
 long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs);
@@ -136,9 +138,6 @@  bool vhost_enable_notify(struct vhost_virtqueue *);
 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
 		    unsigned int log_num, u64 len);
 
-int vhost_init(void);
-void vhost_cleanup(void);
-
 #define vq_err(vq, fmt, ...) do {                                  \
 		pr_debug(pr_fmt(fmt), ##__VA_ARGS__);       \
 		if ((vq)->error_ctx)                               \