net: Add functions netif_reset_xps_queue and netif_set_xps_queue
This patch adds two functions, netif_reset_xps_queue and
netif_set_xps_queue. The main idea behind these two functions is to
provide a mechanism through which drivers can update their defaults in
regards to XPS.
Currently no such mechanism exists and as a result we cannot use XPS for
things such as ATR which would require a basic configuration to start in
which the Tx queues are mapped to CPUs via a 1:1 mapping. With this change
I am making it possible for drivers such as ixgbe to be able to use the XPS
feature by controlling the default configuration.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 29c884a..5ad489d 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -1002,54 +1002,14 @@
return len;
}
-static DEFINE_MUTEX(xps_map_mutex);
-#define xmap_dereference(P) \
- rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
-
static void xps_queue_release(struct netdev_queue *queue)
{
struct net_device *dev = queue->dev;
- struct xps_dev_maps *dev_maps;
- struct xps_map *map;
unsigned long index;
- int i, pos, nonempty = 0;
index = get_netdev_queue_index(queue);
- mutex_lock(&xps_map_mutex);
- dev_maps = xmap_dereference(dev->xps_maps);
-
- if (dev_maps) {
- 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 (pos < map->len) {
- if (map->len > 1)
- map->queues[pos] =
- map->queues[--map->len];
- else {
- RCU_INIT_POINTER(dev_maps->cpu_map[i],
- NULL);
- kfree_rcu(map, rcu);
- map = NULL;
- }
- }
- if (map)
- nonempty = 1;
- }
-
- if (!nonempty) {
- RCU_INIT_POINTER(dev->xps_maps, NULL);
- kfree_rcu(dev_maps, rcu);
- }
- }
- mutex_unlock(&xps_map_mutex);
+ netif_reset_xps_queue(dev, index);
}
static ssize_t store_xps_map(struct netdev_queue *queue,
@@ -1057,13 +1017,9 @@
const char *buf, size_t len)
{
struct net_device *dev = queue->dev;
- cpumask_var_t mask;
- int err, i, cpu, pos, map_len, alloc_len, need_set;
unsigned long index;
- struct xps_map *map, *new_map;
- struct xps_dev_maps *dev_maps, *new_dev_maps;
- int nonempty = 0;
- int numa_node_id = -2;
+ cpumask_var_t mask;
+ int err;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
@@ -1079,105 +1035,11 @@
return err;
}
- new_dev_maps = kzalloc(max_t(unsigned int,
- XPS_DEV_MAPS_SIZE, L1_CACHE_BYTES), GFP_KERNEL);
- if (!new_dev_maps) {
- free_cpumask_var(mask);
- return -ENOMEM;
- }
-
- mutex_lock(&xps_map_mutex);
-
- dev_maps = xmap_dereference(dev->xps_maps);
-
- for_each_possible_cpu(cpu) {
- map = dev_maps ?
- xmap_dereference(dev_maps->cpu_map[cpu]) : NULL;
- new_map = map;
- if (map) {
- for (pos = 0; pos < map->len; pos++)
- if (map->queues[pos] == index)
- break;
- map_len = map->len;
- alloc_len = map->alloc_len;
- } else
- pos = map_len = alloc_len = 0;
-
- need_set = cpumask_test_cpu(cpu, mask) && cpu_online(cpu);
-#ifdef CONFIG_NUMA
- if (need_set) {
- if (numa_node_id == -2)
- numa_node_id = cpu_to_node(cpu);
- else if (numa_node_id != cpu_to_node(cpu))
- numa_node_id = -1;
- }
-#endif
- if (need_set && pos >= map_len) {
- /* Need to add queue to this CPU's map */
- if (map_len >= alloc_len) {
- alloc_len = alloc_len ?
- 2 * alloc_len : XPS_MIN_MAP_ALLOC;
- new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len),
- GFP_KERNEL,
- cpu_to_node(cpu));
- if (!new_map)
- goto error;
- new_map->alloc_len = alloc_len;
- for (i = 0; i < map_len; i++)
- new_map->queues[i] = map->queues[i];
- new_map->len = map_len;
- }
- new_map->queues[new_map->len++] = index;
- } else if (!need_set && pos < map_len) {
- /* Need to remove queue from this CPU's map */
- if (map_len > 1)
- new_map->queues[pos] =
- new_map->queues[--new_map->len];
- else
- new_map = NULL;
- }
- RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], new_map);
- }
-
- /* Cleanup old maps */
- for_each_possible_cpu(cpu) {
- map = dev_maps ?
- xmap_dereference(dev_maps->cpu_map[cpu]) : NULL;
- if (map && xmap_dereference(new_dev_maps->cpu_map[cpu]) != map)
- kfree_rcu(map, rcu);
- if (new_dev_maps->cpu_map[cpu])
- nonempty = 1;
- }
-
- if (nonempty) {
- rcu_assign_pointer(dev->xps_maps, new_dev_maps);
- } else {
- kfree(new_dev_maps);
- RCU_INIT_POINTER(dev->xps_maps, NULL);
- }
-
- if (dev_maps)
- kfree_rcu(dev_maps, rcu);
-
- netdev_queue_numa_node_write(queue, (numa_node_id >= 0) ? numa_node_id :
- NUMA_NO_NODE);
-
- mutex_unlock(&xps_map_mutex);
+ err = netif_set_xps_queue(dev, mask, index);
free_cpumask_var(mask);
- return len;
-error:
- mutex_unlock(&xps_map_mutex);
-
- if (new_dev_maps)
- for_each_possible_cpu(i)
- kfree(rcu_dereference_protected(
- new_dev_maps->cpu_map[i],
- 1));
- kfree(new_dev_maps);
- free_cpumask_var(mask);
- return -ENOMEM;
+ return err ? : len;
}
static struct netdev_queue_attribute xps_cpus_attribute =