Add rps_check_max_queues function which checks is the input number
is greater than rps_max_num_queues. If it is then set max_num_queues
to the value and recreating the sock_flow_table to update the
queue masks used in table entries.
---
include/linux/netdevice.h | 10 ++++++++
net/core/sysctl_net_core.c | 48 ++++++++++++++++++++++++++++++++++++++
2 files changed, 58 insertions(+)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index d528aa61fea3..48ba1c1fc644 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -804,6 +804,16 @@ static inline void rps_record_sock_flow(struct
rps_sock_flow_table *table,
}
}
+int __rps_check_max_queues(unsigned int idx);
+
+static inline int rps_check_max_queues(unsigned int idx)
+{
+ if (idx < rps_max_num_queues)
+ return 0;
+
+ return __rps_check_max_queues(idx);
+}
+
#ifdef CONFIG_RFS_ACCEL
bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index, u32 flow_id,
u16 filter_id);
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
index d09471f29d89..743c46148135 100644
--- a/net/core/sysctl_net_core.c
+++ b/net/core/sysctl_net_core.c
@@ -127,6 +127,54 @@ static int rps_sock_flow_sysctl(struct ctl_table *table,
int write,
return ret;
}
+
+int __rps_check_max_queues(unsigned int idx)
+{
+ unsigned int old;
+ size_t size;
+ int ret = 0;
+
+ /* Assume maximum queues should be a least the number of CPUs.
+ * This avoids too much thrashing of the sock flow table at
+ * initialization.
+ */
+ if (idx < nr_cpu_ids && nr_cpu_ids < RPS_MAX_QID)
+ idx = nr_cpu_ids;
+
+ if (idx > RPS_MAX_QID)
+ return -EINVAL;
+
+ mutex_lock(&sock_flow_mutex);
+
+ old = rps_max_num_queues;
+ rps_max_num_queues = idx;
+
+ /* No need to reallocate table since nothing is changing */
+
+ if (roundup_pow_of_two(old) != roundup_pow_of_two(idx)) {
+ struct rps_sock_flow_table *sock_table;
+
+ sock_table = rcu_dereference_protected(rps_sock_flow_table,
+
lockdep_is_held(&sock_flow_mutex));
+ size = sock_table ? sock_table->mask + 1 : 0;
+
+ /* Force creation of a new rps_sock_flow_table. It's
+ * the same size as the existing table, but we expunge
+ * any stale queue entries that would refer to the old
+ * queue mask.
+ */
+ ret = rps_create_sock_flow_table(size, size,
+ sock_table, true);
+ if (ret)
+ rps_max_num_queues = old;
+ }
+
+ mutex_unlock(&sock_flow_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL(__rps_check_max_queues);
+
#endif /* CONFIG_RPS */
#ifdef CONFIG_NET_FLOW_LIMIT
--
2.25.1
