Commit 10cdc3f3 authored by Alexander Duyck's avatar Alexander Duyck Committed by David S. Miller
Browse files

net: Rewrite netif_reset_xps_queue to allow for better code reuse 



This patch does a minor refactor on netif_reset_xps_queue to address a few
items I noticed.

First is the fact that we are doing removal of queues in both
netif_reset_xps_queue and netif_set_xps_queue.  Since there is no need to
have the code in two places I am pushing it out into a separate function
and will come back in another patch and reuse the code in
netif_set_xps_queue.

The second item this change addresses is the fact that the Tx queues were
not getting their numa_node value cleared as a part of the XPS queue reset.
This patch resolves that by resetting the numa_node value if the dev_maps
value is set.

Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 537c00de

net/core/dev.c

+33 −23
Original line number Diff line number Diff line
@@ -1862,45 +1862,55 @@ static DEFINE_MUTEX(xps_map_mutex); 
#define xmap_dereference(P)		\

	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))



void netif_reset_xps_queue(struct net_device *dev, u16 index)

static struct xps_map *remove_xps_queue(struct xps_dev_maps *dev_maps,

					int cpu, u16 index)

{

	struct xps_dev_maps *dev_maps;

	struct xps_map *map;

	int i, pos, nonempty = 0;



	mutex_lock(&xps_map_mutex);

	dev_maps = xmap_dereference(dev->xps_maps);



	if (!dev_maps)

		goto out_no_maps;

	struct xps_map *map = NULL;

	int pos;



	for_each_possible_cpu(i) {

		map = xmap_dereference(dev_maps->cpu_map[i]);

		if (!map)

			continue;



		for (pos = 0; pos < map->len; pos++)

			if (map->queues[pos] == index)

				break;

	if (dev_maps)

		map = xmap_dereference(dev_maps->cpu_map[cpu]);



		if (pos < map->len) {

	for (pos = 0; map && pos < map->len; pos++) {

		if (map->queues[pos] == index) {

			if (map->len > 1) {

				map->queues[pos] = map->queues[--map->len];

			} else {

				RCU_INIT_POINTER(dev_maps->cpu_map[i], NULL);

				RCU_INIT_POINTER(dev_maps->cpu_map[cpu], NULL);

				kfree_rcu(map, rcu);

				map = NULL;

			}

			break;

		}

		if (map)

			nonempty = 1;

	}



	if (!nonempty) {

	return map;

}



void netif_reset_xps_queue(struct net_device *dev, u16 index)

{

	struct xps_dev_maps *dev_maps;

	int cpu;

	bool active = false;



	mutex_lock(&xps_map_mutex);

	dev_maps = xmap_dereference(dev->xps_maps);



	if (!dev_maps)

		goto out_no_maps;



	for_each_possible_cpu(cpu) {

		if (remove_xps_queue(dev_maps, cpu, index))

			active = true;

	}



	if (!active) {

		RCU_INIT_POINTER(dev->xps_maps, NULL);

		kfree_rcu(dev_maps, rcu);

	}



	netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),

				     NUMA_NO_NODE);

out_no_maps:

	mutex_unlock(&xps_map_mutex);

}

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