net: add gro_cells infrastructure
This adds a new include file (include/net/gro_cells.h), to bring GRO
(Generic Receive Offload) capability to tunnels, in a modular way.
Because tunnels receive path is lockless, and GRO adds a serialization
using a napi_struct, I chose to add an array of up to
DEFAULT_MAX_NUM_RSS_QUEUES cells, so that multi queue devices wont be
slowed down because of GRO layer.
skb_get_rx_queue() is used as selector.
In the future, we might add optional fanout capabilities, using rxhash
for example.
With help from Ben Hutchings who reminded me
netif_get_num_default_rss_queues() function.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 3e645f3..ba4bb11 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2645,6 +2645,8 @@
=======================================================================*/
int netdev_max_backlog __read_mostly = 1000;
+EXPORT_SYMBOL(netdev_max_backlog);
+
int netdev_tstamp_prequeue __read_mostly = 1;
int netdev_budget __read_mostly = 300;
int weight_p __read_mostly = 64; /* old backlog weight */