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| author | Amritha Nambiar | 2018-06-30 06:26:46 +0200 |
|---|---|---|
| committer | David S. Miller | 2018-07-02 02:06:24 +0200 |
| commit | 04157469b7b848f4a9978b63b1ea2ce62ad3a0a3 (patch) | |
| tree | 93bc64865c13a412a70ab8d3412025828a6f732c /net/core | |
| parent | net: Refactor XPS for CPUs and Rx queues (diff) | |
| download | kernel-qcow2-linux-04157469b7b848f4a9978b63b1ea2ce62ad3a0a3.tar.gz kernel-qcow2-linux-04157469b7b848f4a9978b63b1ea2ce62ad3a0a3.tar.xz kernel-qcow2-linux-04157469b7b848f4a9978b63b1ea2ce62ad3a0a3.zip | |
net: Use static_key for XPS maps
Use static_key for XPS maps to reduce the cost of extra map checks,
similar to how it is used for RPS and RFS. This includes static_key
'xps_needed' for XPS and another for 'xps_rxqs_needed' for XPS using
Rx queues map.
Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/dev.c | 31 |
1 files changed, 25 insertions, 6 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 71059558dc39..43b5575e40c5 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2081,6 +2081,10 @@ int netdev_txq_to_tc(struct net_device *dev, unsigned int txq) EXPORT_SYMBOL(netdev_txq_to_tc); #ifdef CONFIG_XPS +struct static_key xps_needed __read_mostly; +EXPORT_SYMBOL(xps_needed); +struct static_key xps_rxqs_needed __read_mostly; +EXPORT_SYMBOL(xps_rxqs_needed); static DEFINE_MUTEX(xps_map_mutex); #define xmap_dereference(P) \ rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex)) @@ -2168,14 +2172,18 @@ static void netif_reset_xps_queues(struct net_device *dev, u16 offset, struct xps_dev_maps *dev_maps; unsigned int nr_ids; - mutex_lock(&xps_map_mutex); + if (!static_key_false(&xps_needed)) + return; - dev_maps = xmap_dereference(dev->xps_rxqs_map); - if (dev_maps) { - nr_ids = dev->num_rx_queues; - clean_xps_maps(dev, possible_mask, dev_maps, nr_ids, offset, - count, true); + mutex_lock(&xps_map_mutex); + if (static_key_false(&xps_rxqs_needed)) { + dev_maps = xmap_dereference(dev->xps_rxqs_map); + if (dev_maps) { + nr_ids = dev->num_rx_queues; + clean_xps_maps(dev, possible_mask, dev_maps, nr_ids, + offset, count, true); + } } dev_maps = xmap_dereference(dev->xps_cpus_map); @@ -2189,6 +2197,10 @@ static void netif_reset_xps_queues(struct net_device *dev, u16 offset, false); out_no_maps: + if (static_key_enabled(&xps_rxqs_needed)) + static_key_slow_dec(&xps_rxqs_needed); + + static_key_slow_dec(&xps_needed); mutex_unlock(&xps_map_mutex); } @@ -2297,6 +2309,10 @@ int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask, if (!new_dev_maps) goto out_no_new_maps; + static_key_slow_inc(&xps_needed); + if (is_rxqs_map) + static_key_slow_inc(&xps_rxqs_needed); + for (j = -1; j = netif_attrmask_next(j, possible_mask, nr_ids), j < nr_ids;) { /* copy maps belonging to foreign traffic classes */ @@ -3450,6 +3466,9 @@ static inline int get_xps_queue(struct net_device *dev, struct sk_buff *skb) struct xps_map *map; int queue_index = -1; + if (!static_key_false(&xps_needed)) + return -1; + rcu_read_lock(); dev_maps = rcu_dereference(dev->xps_cpus_map); if (dev_maps) { |