net: allow large number of tx queues
netif_alloc_netdev_queues() uses kcalloc() to allocate memory
for the "struct netdev_queue *_tx" array.
For large number of tx queues, kcalloc() might fail, so this
patch does a fallback to vzalloc().
As vmalloc() adds overhead on a critical network path, add __GFP_REPEAT
to kzalloc() flags to do this fallback only when really needed.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index fa007db..722f633 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -130,6 +130,7 @@
#include <linux/cpu_rmap.h>
#include <linux/static_key.h>
#include <linux/hashtable.h>
+#include <linux/vmalloc.h>
#include "net-sysfs.h"
@@ -5253,17 +5254,28 @@
#endif
}
+static void netif_free_tx_queues(struct net_device *dev)
+{
+ if (is_vmalloc_addr(dev->_tx))
+ vfree(dev->_tx);
+ else
+ kfree(dev->_tx);
+}
+
static int netif_alloc_netdev_queues(struct net_device *dev)
{
unsigned int count = dev->num_tx_queues;
struct netdev_queue *tx;
+ size_t sz = count * sizeof(*tx);
- BUG_ON(count < 1);
+ BUG_ON(count < 1 || count > 0xffff);
- tx = kcalloc(count, sizeof(struct netdev_queue), GFP_KERNEL);
- if (!tx)
- return -ENOMEM;
-
+ tx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
+ if (!tx) {
+ tx = vzalloc(sz);
+ if (!tx)
+ return -ENOMEM;
+ }
dev->_tx = tx;
netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
@@ -5811,7 +5823,7 @@
free_pcpu:
free_percpu(dev->pcpu_refcnt);
- kfree(dev->_tx);
+ netif_free_tx_queues(dev);
#ifdef CONFIG_RPS
kfree(dev->_rx);
#endif
@@ -5836,7 +5848,7 @@
release_net(dev_net(dev));
- kfree(dev->_tx);
+ netif_free_tx_queues(dev);
#ifdef CONFIG_RPS
kfree(dev->_rx);
#endif