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>
This commit is contained in:
Alexander Duyck
David S. Miller
parent
416186fbf8
commit
537c00de1c
@ -2103,6 +2103,19 @@ static inline void netif_wake_subqueue(struct net_device *dev, u16 queue_index)
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__netif_schedule(txq->qdisc);
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}
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#ifdef CONFIG_XPS
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extern void netif_reset_xps_queue(struct net_device *dev, u16 index);
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extern int netif_set_xps_queue(struct net_device *dev, struct cpumask *mask,
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u16 index);
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#else
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static inline int netif_set_xps_queue(struct net_device *dev,
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struct cpumask *mask,
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u16 index)
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{
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return 0;
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}
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#endif
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/*
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* Returns a Tx hash for the given packet when dev->real_num_tx_queues is used
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* as a distribution range limit for the returned value.
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155
net/core/dev.c
155
net/core/dev.c
@ -1857,6 +1857,161 @@ static void netif_setup_tc(struct net_device *dev, unsigned int txq)
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}
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}
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#ifdef CONFIG_XPS
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static DEFINE_MUTEX(xps_map_mutex);
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#define xmap_dereference(P) \
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rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
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void netif_reset_xps_queue(struct net_device *dev, u16 index)
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{
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struct xps_dev_maps *dev_maps;
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struct xps_map *map;
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int i, pos, nonempty = 0;
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mutex_lock(&xps_map_mutex);
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dev_maps = xmap_dereference(dev->xps_maps);
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if (!dev_maps)
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goto out_no_maps;
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for_each_possible_cpu(i) {
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map = xmap_dereference(dev_maps->cpu_map[i]);
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if (!map)
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continue;
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for (pos = 0; pos < map->len; pos++)
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if (map->queues[pos] == index)
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break;
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if (pos < map->len) {
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if (map->len > 1) {
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map->queues[pos] = map->queues[--map->len];
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} else {
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RCU_INIT_POINTER(dev_maps->cpu_map[i], NULL);
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kfree_rcu(map, rcu);
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map = NULL;
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}
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}
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if (map)
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nonempty = 1;
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}
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if (!nonempty) {
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RCU_INIT_POINTER(dev->xps_maps, NULL);
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kfree_rcu(dev_maps, rcu);
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}
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out_no_maps:
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mutex_unlock(&xps_map_mutex);
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}
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int netif_set_xps_queue(struct net_device *dev, struct cpumask *mask, u16 index)
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{
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int i, cpu, pos, map_len, alloc_len, need_set;
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struct xps_map *map, *new_map;
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struct xps_dev_maps *dev_maps, *new_dev_maps;
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int nonempty = 0;
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int numa_node_id = -2;
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int maps_sz = max_t(unsigned int, XPS_DEV_MAPS_SIZE, L1_CACHE_BYTES);
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new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
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if (!new_dev_maps)
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return -ENOMEM;
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mutex_lock(&xps_map_mutex);
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dev_maps = xmap_dereference(dev->xps_maps);
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for_each_possible_cpu(cpu) {
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map = dev_maps ?
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xmap_dereference(dev_maps->cpu_map[cpu]) : NULL;
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new_map = map;
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if (map) {
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for (pos = 0; pos < map->len; pos++)
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if (map->queues[pos] == index)
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break;
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map_len = map->len;
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alloc_len = map->alloc_len;
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} else
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pos = map_len = alloc_len = 0;
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need_set = cpumask_test_cpu(cpu, mask) && cpu_online(cpu);
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#ifdef CONFIG_NUMA
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if (need_set) {
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if (numa_node_id == -2)
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numa_node_id = cpu_to_node(cpu);
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else if (numa_node_id != cpu_to_node(cpu))
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numa_node_id = -1;
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}
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#endif
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if (need_set && pos >= map_len) {
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/* Need to add queue to this CPU's map */
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if (map_len >= alloc_len) {
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alloc_len = alloc_len ?
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2 * alloc_len : XPS_MIN_MAP_ALLOC;
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new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len),
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GFP_KERNEL,
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cpu_to_node(cpu));
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if (!new_map)
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goto error;
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new_map->alloc_len = alloc_len;
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for (i = 0; i < map_len; i++)
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new_map->queues[i] = map->queues[i];
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new_map->len = map_len;
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}
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new_map->queues[new_map->len++] = index;
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} else if (!need_set && pos < map_len) {
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/* Need to remove queue from this CPU's map */
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if (map_len > 1)
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new_map->queues[pos] =
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new_map->queues[--new_map->len];
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else
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new_map = NULL;
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}
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RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], new_map);
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}
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/* Cleanup old maps */
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for_each_possible_cpu(cpu) {
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map = dev_maps ?
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xmap_dereference(dev_maps->cpu_map[cpu]) : NULL;
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if (map && xmap_dereference(new_dev_maps->cpu_map[cpu]) != map)
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kfree_rcu(map, rcu);
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if (new_dev_maps->cpu_map[cpu])
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nonempty = 1;
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}
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if (nonempty) {
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rcu_assign_pointer(dev->xps_maps, new_dev_maps);
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} else {
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kfree(new_dev_maps);
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RCU_INIT_POINTER(dev->xps_maps, NULL);
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}
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if (dev_maps)
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kfree_rcu(dev_maps, rcu);
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netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
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(numa_node_id >= 0) ? numa_node_id :
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NUMA_NO_NODE);
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mutex_unlock(&xps_map_mutex);
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return 0;
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error:
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mutex_unlock(&xps_map_mutex);
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if (new_dev_maps)
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for_each_possible_cpu(i)
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kfree(rcu_dereference_protected(
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new_dev_maps->cpu_map[i],
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1));
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kfree(new_dev_maps);
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return -ENOMEM;
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}
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EXPORT_SYMBOL(netif_set_xps_queue);
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#endif
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/*
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* Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
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* greater then real_num_tx_queues stale skbs on the qdisc must be flushed.
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@ -1002,54 +1002,14 @@ static ssize_t show_xps_map(struct netdev_queue *queue,
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return len;
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}
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static DEFINE_MUTEX(xps_map_mutex);
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#define xmap_dereference(P) \
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rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
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static void xps_queue_release(struct netdev_queue *queue)
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{
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struct net_device *dev = queue->dev;
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struct xps_dev_maps *dev_maps;
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struct xps_map *map;
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unsigned long index;
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int i, pos, nonempty = 0;
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index = get_netdev_queue_index(queue);
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mutex_lock(&xps_map_mutex);
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dev_maps = xmap_dereference(dev->xps_maps);
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if (dev_maps) {
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for_each_possible_cpu(i) {
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map = xmap_dereference(dev_maps->cpu_map[i]);
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if (!map)
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continue;
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for (pos = 0; pos < map->len; pos++)
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if (map->queues[pos] == index)
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break;
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if (pos < map->len) {
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if (map->len > 1)
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map->queues[pos] =
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map->queues[--map->len];
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else {
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RCU_INIT_POINTER(dev_maps->cpu_map[i],
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NULL);
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kfree_rcu(map, rcu);
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map = NULL;
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}
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}
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if (map)
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nonempty = 1;
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}
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if (!nonempty) {
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RCU_INIT_POINTER(dev->xps_maps, NULL);
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kfree_rcu(dev_maps, rcu);
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}
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}
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mutex_unlock(&xps_map_mutex);
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netif_reset_xps_queue(dev, index);
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}
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static ssize_t store_xps_map(struct netdev_queue *queue,
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@ -1057,13 +1017,9 @@ static ssize_t store_xps_map(struct netdev_queue *queue,
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const char *buf, size_t len)
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{
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struct net_device *dev = queue->dev;
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cpumask_var_t mask;
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int err, i, cpu, pos, map_len, alloc_len, need_set;
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unsigned long index;
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struct xps_map *map, *new_map;
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struct xps_dev_maps *dev_maps, *new_dev_maps;
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int nonempty = 0;
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int numa_node_id = -2;
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cpumask_var_t mask;
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int err;
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if (!capable(CAP_NET_ADMIN))
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return -EPERM;
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@ -1079,105 +1035,11 @@ static ssize_t store_xps_map(struct netdev_queue *queue,
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return err;
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}
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new_dev_maps = kzalloc(max_t(unsigned int,
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XPS_DEV_MAPS_SIZE, L1_CACHE_BYTES), GFP_KERNEL);
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if (!new_dev_maps) {
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free_cpumask_var(mask);
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return -ENOMEM;
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}
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mutex_lock(&xps_map_mutex);
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dev_maps = xmap_dereference(dev->xps_maps);
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for_each_possible_cpu(cpu) {
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map = dev_maps ?
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xmap_dereference(dev_maps->cpu_map[cpu]) : NULL;
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new_map = map;
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if (map) {
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for (pos = 0; pos < map->len; pos++)
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if (map->queues[pos] == index)
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break;
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map_len = map->len;
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alloc_len = map->alloc_len;
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} else
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pos = map_len = alloc_len = 0;
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need_set = cpumask_test_cpu(cpu, mask) && cpu_online(cpu);
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#ifdef CONFIG_NUMA
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if (need_set) {
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if (numa_node_id == -2)
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numa_node_id = cpu_to_node(cpu);
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else if (numa_node_id != cpu_to_node(cpu))
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numa_node_id = -1;
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}
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#endif
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if (need_set && pos >= map_len) {
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/* Need to add queue to this CPU's map */
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if (map_len >= alloc_len) {
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alloc_len = alloc_len ?
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2 * alloc_len : XPS_MIN_MAP_ALLOC;
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new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len),
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GFP_KERNEL,
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cpu_to_node(cpu));
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if (!new_map)
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goto error;
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new_map->alloc_len = alloc_len;
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for (i = 0; i < map_len; i++)
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new_map->queues[i] = map->queues[i];
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new_map->len = map_len;
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}
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new_map->queues[new_map->len++] = index;
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} else if (!need_set && pos < map_len) {
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/* Need to remove queue from this CPU's map */
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if (map_len > 1)
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new_map->queues[pos] =
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new_map->queues[--new_map->len];
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else
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new_map = NULL;
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}
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RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], new_map);
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}
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/* Cleanup old maps */
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for_each_possible_cpu(cpu) {
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map = dev_maps ?
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xmap_dereference(dev_maps->cpu_map[cpu]) : NULL;
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if (map && xmap_dereference(new_dev_maps->cpu_map[cpu]) != map)
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kfree_rcu(map, rcu);
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if (new_dev_maps->cpu_map[cpu])
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nonempty = 1;
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}
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if (nonempty) {
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rcu_assign_pointer(dev->xps_maps, new_dev_maps);
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} else {
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kfree(new_dev_maps);
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RCU_INIT_POINTER(dev->xps_maps, NULL);
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}
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if (dev_maps)
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kfree_rcu(dev_maps, rcu);
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netdev_queue_numa_node_write(queue, (numa_node_id >= 0) ? numa_node_id :
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NUMA_NO_NODE);
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mutex_unlock(&xps_map_mutex);
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err = netif_set_xps_queue(dev, mask, index);
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free_cpumask_var(mask);
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return len;
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error:
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mutex_unlock(&xps_map_mutex);
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if (new_dev_maps)
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for_each_possible_cpu(i)
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kfree(rcu_dereference_protected(
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new_dev_maps->cpu_map[i],
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1));
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kfree(new_dev_maps);
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free_cpumask_var(mask);
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return -ENOMEM;
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return err ? : len;
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}
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static struct netdev_queue_attribute xps_cpus_attribute =
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