Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit edafc132 authored by Palik, Imre's avatar Palik, Imre Committed by David S. Miller
Browse files

xen-netback: making the bandwidth limiter runtime settable 



With the current netback, the bandwidth limiter's parameters are only
settable during vif setup time.  This patch register a watch on them, and
thus makes them runtime changeable.

When the watch fires, the timer is reset.  The timer's mutex is used for
fencing the change.

Cc: Anthony Liguori <aliguori@amazon.com>
Signed-off-by: default avatarImre Palik <imrep@amazon.de>
Acked-by: default avatarWei Liu <wei.liu2@citrix.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 750f2f91

drivers/net/xen-netback/common.h

+4 −0
Original line number Original line Diff line number Diff line
@@ -238,6 +238,8 @@ struct xenvif { 
	unsigned int num_queues; /* active queues, resource allocated */

	unsigned int num_queues; /* active queues, resource allocated */

	unsigned int stalled_queues;

	unsigned int stalled_queues;





	struct xenbus_watch credit_watch;



	spinlock_t lock;

	spinlock_t lock;





#ifdef CONFIG_DEBUG_FS

#ifdef CONFIG_DEBUG_FS
@@ -260,6 +262,8 @@ static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif) 
	return to_xenbus_device(vif->dev->dev.parent);

	return to_xenbus_device(vif->dev->dev.parent);

}

}





void xenvif_tx_credit_callback(unsigned long data);



struct xenvif *xenvif_alloc(struct device *parent,

struct xenvif *xenvif_alloc(struct device *parent,

			    domid_t domid,

			    domid_t domid,

			    unsigned int handle);

			    unsigned int handle);

drivers/net/xen-netback/interface.c

+1 −0
Original line number Original line Diff line number Diff line
@@ -463,6 +463,7 @@ int xenvif_init_queue(struct xenvif_queue *queue) 
	queue->credit_bytes = queue->remaining_credit = ~0UL;

	queue->credit_bytes = queue->remaining_credit = ~0UL;

	queue->credit_usec  = 0UL;

	queue->credit_usec  = 0UL;

	init_timer(&queue->credit_timeout);

	init_timer(&queue->credit_timeout);

	queue->credit_timeout.function = xenvif_tx_credit_callback;

	queue->credit_window_start = get_jiffies_64();

	queue->credit_window_start = get_jiffies_64();





	queue->rx_queue_max = XENVIF_RX_QUEUE_BYTES;

	queue->rx_queue_max = XENVIF_RX_QUEUE_BYTES;

drivers/net/xen-netback/netback.c

+1 −3
Original line number Original line Diff line number Diff line
@@ -641,7 +641,7 @@ static void tx_add_credit(struct xenvif_queue *queue) 
	queue->remaining_credit = min(max_credit, max_burst);

	queue->remaining_credit = min(max_credit, max_burst);

}

}





static void tx_credit_callback(unsigned long data)

void xenvif_tx_credit_callback(unsigned long data)

{

{

	struct xenvif_queue *queue = (struct xenvif_queue *)data;

	struct xenvif_queue *queue = (struct xenvif_queue *)data;

	tx_add_credit(queue);

	tx_add_credit(queue);
@@ -1169,8 +1169,6 @@ static bool tx_credit_exceeded(struct xenvif_queue *queue, unsigned size) 
	if (size > queue->remaining_credit) {

	if (size > queue->remaining_credit) {

		queue->credit_timeout.data     =

		queue->credit_timeout.data     =

			(unsigned long)queue;

			(unsigned long)queue;

		queue->credit_timeout.function =

			tx_credit_callback;

		mod_timer(&queue->credit_timeout,

		mod_timer(&queue->credit_timeout,

			  next_credit);

			  next_credit);

		queue->credit_window_start = next_credit;

		queue->credit_window_start = next_credit;

drivers/net/xen-netback/xenbus.c

+57 −0
Original line number Original line Diff line number Diff line
@@ -41,6 +41,7 @@ static void connect(struct backend_info *be); 
static int read_xenbus_vif_flags(struct backend_info *be);

static int read_xenbus_vif_flags(struct backend_info *be);

static int backend_create_xenvif(struct backend_info *be);

static int backend_create_xenvif(struct backend_info *be);

static void unregister_hotplug_status_watch(struct backend_info *be);

static void unregister_hotplug_status_watch(struct backend_info *be);

static void xen_unregister_watchers(struct xenvif *vif);

static void set_backend_state(struct backend_info *be,

static void set_backend_state(struct backend_info *be,

			      enum xenbus_state state);

			      enum xenbus_state state);
@@ -232,6 +233,7 @@ static int netback_remove(struct xenbus_device *dev) 
	unregister_hotplug_status_watch(be);

	unregister_hotplug_status_watch(be);

	if (be->vif) {

	if (be->vif) {

		kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);

		kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);

		xen_unregister_watchers(be->vif);

		xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");

		xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");

		xenvif_free(be->vif);

		xenvif_free(be->vif);

		be->vif = NULL;

		be->vif = NULL;
@@ -430,6 +432,7 @@ static int backend_create_xenvif(struct backend_info *be) 
static void backend_disconnect(struct backend_info *be)

static void backend_disconnect(struct backend_info *be)

{

{

	if (be->vif) {

	if (be->vif) {

		xen_unregister_watchers(be->vif);

#ifdef CONFIG_DEBUG_FS

#ifdef CONFIG_DEBUG_FS

		xenvif_debugfs_delif(be->vif);

		xenvif_debugfs_delif(be->vif);

#endif /* CONFIG_DEBUG_FS */

#endif /* CONFIG_DEBUG_FS */
@@ -645,6 +648,59 @@ static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) 
	return 0;

	return 0;

}

}





static void xen_net_rate_changed(struct xenbus_watch *watch,

				const char **vec, unsigned int len)

{

	struct xenvif *vif = container_of(watch, struct xenvif, credit_watch);

	struct xenbus_device *dev = xenvif_to_xenbus_device(vif);

	unsigned long   credit_bytes;

	unsigned long   credit_usec;

	unsigned int queue_index;



	xen_net_read_rate(dev, &credit_bytes, &credit_usec);

	for (queue_index = 0; queue_index < vif->num_queues; queue_index++) {

		struct xenvif_queue *queue = &vif->queues[queue_index];



		queue->credit_bytes = credit_bytes;

		queue->credit_usec = credit_usec;

		if (!mod_timer_pending(&queue->credit_timeout, jiffies) &&

			queue->remaining_credit > queue->credit_bytes) {

			queue->remaining_credit = queue->credit_bytes;

		}

	}

}



static int xen_register_watchers(struct xenbus_device *dev, struct xenvif *vif)

{

	int err = 0;

	char *node;

	unsigned maxlen = strlen(dev->nodename) + sizeof("/rate");



	node = kmalloc(maxlen, GFP_KERNEL);

	if (!node)

		return -ENOMEM;

	snprintf(node, maxlen, "%s/rate", dev->nodename);

	vif->credit_watch.node = node;

	vif->credit_watch.callback = xen_net_rate_changed;

	err = register_xenbus_watch(&vif->credit_watch);

	if (err) {

		pr_err("Failed to set watcher %s\n", vif->credit_watch.node);

		kfree(node);

		vif->credit_watch.node = NULL;

		vif->credit_watch.callback = NULL;

	}

	return err;

}



static void xen_unregister_watchers(struct xenvif *vif)

{

	if (vif->credit_watch.node) {

		unregister_xenbus_watch(&vif->credit_watch);

		kfree(vif->credit_watch.node);

		vif->credit_watch.node = NULL;

	}

}



static void unregister_hotplug_status_watch(struct backend_info *be)

static void unregister_hotplug_status_watch(struct backend_info *be)

{

{

	if (be->have_hotplug_status_watch) {

	if (be->have_hotplug_status_watch) {
@@ -709,6 +765,7 @@ static void connect(struct backend_info *be) 
	}

	}





	xen_net_read_rate(dev, &credit_bytes, &credit_usec);

	xen_net_read_rate(dev, &credit_bytes, &credit_usec);

	xen_register_watchers(dev, be->vif);

	read_xenbus_vif_flags(be);

	read_xenbus_vif_flags(be);





	/* Use the number of queues requested by the frontend */

	/* Use the number of queues requested by the frontend */