diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 8cbe96ce0a2c..e01a8ce7181f 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3664,7 +3664,6 @@ static inline unsigned int get_netdev_rx_queue_index( } #endif -#define DEFAULT_MAX_NUM_RSS_QUEUES (8) int netif_get_num_default_rss_queues(void); enum skb_free_reason { diff --git a/net/core/dev.c b/net/core/dev.c index 75bab5b0dbae..8e0cc5f2020d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2990,13 +2990,25 @@ EXPORT_SYMBOL(netif_set_real_num_queues); /** * netif_get_num_default_rss_queues - default number of RSS queues * - * This routine should set an upper limit on the number of RSS queues - * used by default by multiqueue devices. + * Default value is the number of physical cores if there are only 1 or 2, or + * divided by 2 if there are more. */ int netif_get_num_default_rss_queues(void) { - return is_kdump_kernel() ? - 1 : min_t(int, DEFAULT_MAX_NUM_RSS_QUEUES, num_online_cpus()); + cpumask_var_t cpus; + int cpu, count = 0; + + if (unlikely(is_kdump_kernel() || !zalloc_cpumask_var(&cpus, GFP_KERNEL))) + return 1; + + cpumask_copy(cpus, cpu_online_mask); + for_each_cpu(cpu, cpus) { + ++count; + cpumask_andnot(cpus, cpus, topology_sibling_cpumask(cpu)); + } + free_cpumask_var(cpus); + + return count > 2 ? DIV_ROUND_UP(count, 2) : count; } EXPORT_SYMBOL(netif_get_num_default_rss_queues);