Example #1
1
static int balloon(void *_vballoon)
{
	struct virtio_balloon *vb = _vballoon;
	DEFINE_WAIT_FUNC(wait, woken_wake_function);

	set_freezable();
	while (!kthread_should_stop()) {
		s64 diff;

		try_to_freeze();

		add_wait_queue(&vb->config_change, &wait);
		for (;;) {
			if ((diff = towards_target(vb)) != 0 ||
			    vb->need_stats_update ||
			    kthread_should_stop() ||
			    freezing(current))
				break;
			wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
		}
		remove_wait_queue(&vb->config_change, &wait);

		if (vb->need_stats_update)
			stats_handle_request(vb);
		if (diff > 0)
			fill_balloon(vb, diff);
		else if (diff < 0)
			leak_balloon(vb, -diff);
		update_balloon_size(vb);

		/*
		 * For large balloon changes, we could spend a lot of time
		 * and always have work to do.  Be nice if preempt disabled.
		 */
		cond_resched();
	}
	return 0;
}
Example #2
0
static void virtballoon_changed(struct virtio_device *vdev)
{
	struct virtio_balloon *vb = vdev->priv;
	unsigned long flags;
	s64 diff = towards_target(vb);

	if (diff) {
		spin_lock_irqsave(&vb->stop_update_lock, flags);
		if (!vb->stop_update)
			queue_work(system_freezable_wq,
				   &vb->update_balloon_size_work);
		spin_unlock_irqrestore(&vb->stop_update_lock, flags);
	}

	if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
		virtio_cread(vdev, struct virtio_balloon_config,
			     free_page_report_cmd_id, &vb->cmd_id_received);
		if (vb->cmd_id_received == VIRTIO_BALLOON_CMD_ID_DONE) {
			/* Pass ULONG_MAX to give back all the free pages */
			return_free_pages_to_mm(vb, ULONG_MAX);
		} else if (vb->cmd_id_received != VIRTIO_BALLOON_CMD_ID_STOP &&
			   vb->cmd_id_received !=
			   virtio32_to_cpu(vdev, vb->cmd_id_active)) {
			spin_lock_irqsave(&vb->stop_update_lock, flags);
			if (!vb->stop_update) {
				queue_work(vb->balloon_wq,
					   &vb->report_free_page_work);
			}
			spin_unlock_irqrestore(&vb->stop_update_lock, flags);
		}
	}
}
static int balloon(void *_vballoon)
{
	struct virtio_balloon *vb = _vballoon;

	set_freezable();
	while (!kthread_should_stop()) {
		s64 diff;

		try_to_freeze();
		wait_event_interruptible(vb->config_change,
					 (diff = towards_target(vb)) != 0
					 || vb->need_stats_update
					 || kthread_should_stop()
					 || freezing(current));
		if (vb->need_stats_update)
			stats_handle_request(vb);
		if (diff > 0)
			fill_balloon(vb, diff);
		else if (diff < 0)
			leak_balloon(vb, -diff);
		update_balloon_size(vb);

		/*
		 * For large balloon changes, we could spend a lot of time
		 * and always have work to do.  Be nice if preempt disabled.
		 */
		cond_resched();
	}
	return 0;
}
Example #4
0
static int virtballoon_restore(struct virtio_device *vdev)
{
	struct virtio_balloon *vb = vdev->priv;
	int ret;

	ret = init_vqs(vdev->priv);
	if (ret)
		return ret;

	fill_balloon(vb, towards_target(vb));
	update_balloon_size(vb);
	return 0;
}
Example #5
0
static void update_balloon_size_func(struct work_struct *work)
{
	struct virtio_balloon *vb;
	s64 diff;

	vb = container_of(work, struct virtio_balloon,
			  update_balloon_size_work);
	diff = towards_target(vb);

	if (diff > 0)
		diff -= fill_balloon(vb, diff);
	else if (diff < 0)
		diff += leak_balloon(vb, -diff);
	update_balloon_size(vb);

	if (diff)
		queue_work(system_freezable_wq, work);
}
Example #6
0
static int balloon(void *_vballoon)
{
	struct virtio_balloon *vb = _vballoon;

	set_freezable();
	while (!kthread_should_stop()) {
		s64 diff;

		try_to_freeze();
		wait_event_interruptible(vb->config_change,
					 (diff = towards_target(vb)) != 0
					 || vb->need_stats_update
					 || kthread_should_stop()
					 || freezing(current));
		if (vb->need_stats_update)
			stats_handle_request(vb);
		if (diff > 0)
			fill_balloon(vb, diff);
		else if (diff < 0)
			leak_balloon(vb, -diff);
		update_balloon_size(vb);
	}
	return 0;
}
Example #7
0
static int virtballoon_probe(struct virtio_device *vdev)
{
	struct virtio_balloon *vb;
	__u32 poison_val;
	int err;

	if (!vdev->config->get) {
		dev_err(&vdev->dev, "%s failure: config access disabled\n",
			__func__);
		return -EINVAL;
	}

	vdev->priv = vb = kzalloc(sizeof(*vb), GFP_KERNEL);
	if (!vb) {
		err = -ENOMEM;
		goto out;
	}

	INIT_WORK(&vb->update_balloon_stats_work, update_balloon_stats_func);
	INIT_WORK(&vb->update_balloon_size_work, update_balloon_size_func);
	spin_lock_init(&vb->stop_update_lock);
	mutex_init(&vb->balloon_lock);
	init_waitqueue_head(&vb->acked);
	vb->vdev = vdev;

	balloon_devinfo_init(&vb->vb_dev_info);

	err = init_vqs(vb);
	if (err)
		goto out_free_vb;

#ifdef CONFIG_BALLOON_COMPACTION
	balloon_mnt = kern_mount(&balloon_fs);
	if (IS_ERR(balloon_mnt)) {
		err = PTR_ERR(balloon_mnt);
		goto out_del_vqs;
	}

	vb->vb_dev_info.migratepage = virtballoon_migratepage;
	vb->vb_dev_info.inode = alloc_anon_inode(balloon_mnt->mnt_sb);
	if (IS_ERR(vb->vb_dev_info.inode)) {
		err = PTR_ERR(vb->vb_dev_info.inode);
		kern_unmount(balloon_mnt);
		goto out_del_vqs;
	}
	vb->vb_dev_info.inode->i_mapping->a_ops = &balloon_aops;
#endif
	if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
		/*
		 * There is always one entry reserved for cmd id, so the ring
		 * size needs to be at least two to report free page hints.
		 */
		if (virtqueue_get_vring_size(vb->free_page_vq) < 2) {
			err = -ENOSPC;
			goto out_del_vqs;
		}
		vb->balloon_wq = alloc_workqueue("balloon-wq",
					WQ_FREEZABLE | WQ_CPU_INTENSIVE, 0);
		if (!vb->balloon_wq) {
			err = -ENOMEM;
			goto out_del_vqs;
		}
		INIT_WORK(&vb->report_free_page_work, report_free_page_func);
		vb->cmd_id_received = VIRTIO_BALLOON_CMD_ID_STOP;
		vb->cmd_id_active = cpu_to_virtio32(vb->vdev,
						  VIRTIO_BALLOON_CMD_ID_STOP);
		vb->cmd_id_stop = cpu_to_virtio32(vb->vdev,
						  VIRTIO_BALLOON_CMD_ID_STOP);
		vb->num_free_page_blocks = 0;
		spin_lock_init(&vb->free_page_list_lock);
		INIT_LIST_HEAD(&vb->free_page_list);
		if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) {
			memset(&poison_val, PAGE_POISON, sizeof(poison_val));
			virtio_cwrite(vb->vdev, struct virtio_balloon_config,
				      poison_val, &poison_val);
		}
	}
	/*
	 * We continue to use VIRTIO_BALLOON_F_DEFLATE_ON_OOM to decide if a
	 * shrinker needs to be registered to relieve memory pressure.
	 */
	if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) {
		err = virtio_balloon_register_shrinker(vb);
		if (err)
			goto out_del_balloon_wq;
	}
	virtio_device_ready(vdev);

	if (towards_target(vb))
		virtballoon_changed(vdev);
	return 0;

out_del_balloon_wq:
	if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
		destroy_workqueue(vb->balloon_wq);
out_del_vqs:
	vdev->config->del_vqs(vdev);
out_free_vb:
	kfree(vb);
out:
	return err;
}
Example #8
0
static int virtballoon_probe(struct virtio_device *vdev)
{
	struct virtio_balloon *vb;
	int err;

	if (!vdev->config->get) {
		dev_err(&vdev->dev, "%s failure: config access disabled\n",
			__func__);
		return -EINVAL;
	}

	vdev->priv = vb = kmalloc(sizeof(*vb), GFP_KERNEL);
	if (!vb) {
		err = -ENOMEM;
		goto out;
	}

	INIT_WORK(&vb->update_balloon_stats_work, update_balloon_stats_func);
	INIT_WORK(&vb->update_balloon_size_work, update_balloon_size_func);
	spin_lock_init(&vb->stop_update_lock);
	vb->stop_update = false;
	vb->num_pages = 0;
	mutex_init(&vb->balloon_lock);
	init_waitqueue_head(&vb->acked);
	vb->vdev = vdev;

	balloon_devinfo_init(&vb->vb_dev_info);

	err = init_vqs(vb);
	if (err)
		goto out_free_vb;

	vb->nb.notifier_call = virtballoon_oom_notify;
	vb->nb.priority = VIRTBALLOON_OOM_NOTIFY_PRIORITY;
	err = register_oom_notifier(&vb->nb);
	if (err < 0)
		goto out_del_vqs;

#ifdef CONFIG_BALLOON_COMPACTION
	balloon_mnt = kern_mount(&balloon_fs);
	if (IS_ERR(balloon_mnt)) {
		err = PTR_ERR(balloon_mnt);
		unregister_oom_notifier(&vb->nb);
		goto out_del_vqs;
	}

	vb->vb_dev_info.migratepage = virtballoon_migratepage;
	vb->vb_dev_info.inode = alloc_anon_inode(balloon_mnt->mnt_sb);
	if (IS_ERR(vb->vb_dev_info.inode)) {
		err = PTR_ERR(vb->vb_dev_info.inode);
		kern_unmount(balloon_mnt);
		unregister_oom_notifier(&vb->nb);
		vb->vb_dev_info.inode = NULL;
		goto out_del_vqs;
	}
	vb->vb_dev_info.inode->i_mapping->a_ops = &balloon_aops;
#endif

	virtio_device_ready(vdev);

	if (towards_target(vb))
		virtballoon_changed(vdev);
	return 0;

out_del_vqs:
	vdev->config->del_vqs(vdev);
out_free_vb:
	kfree(vb);
out:
	return err;
}