net: use listified RX for handling GRO_NORMAL skbs

When GRO decides not to coalesce a packet, in napi_frags_finish(), instead
 of passing it to the stack immediately, place it on a list in the napi
 struct.  Then, at flush time (napi_complete_done(), napi_poll(), or
 napi_busy_loop()), call netif_receive_skb_list_internal() on the list.
We'd like to do that in napi_gro_flush(), but it's not called if
 !napi->gro_bitmask, so we have to do it in the callers instead.  (There are
 a handful of drivers that call napi_gro_flush() themselves, but it's not
 clear why, or whether this will affect them.)
Because a full 64 packets is an inefficiently large batch, also consume the
 list whenever it exceeds gro_normal_batch, a new net/core sysctl that
 defaults to 8.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Edward Cree
2019-08-06 14:53:55 +01:00
committed by David S. Miller
parent 6727013694
commit 323ebb61e3
3 changed files with 52 additions and 3 deletions

View File

@@ -332,6 +332,8 @@ struct napi_struct {
struct net_device *dev;
struct gro_list gro_hash[GRO_HASH_BUCKETS];
struct sk_buff *skb;
struct list_head rx_list; /* Pending GRO_NORMAL skbs */
int rx_count; /* length of rx_list */
struct hrtimer timer;
struct list_head dev_list;
struct hlist_node napi_hash_node;
@@ -4239,6 +4241,7 @@ extern int dev_weight_rx_bias;
extern int dev_weight_tx_bias;
extern int dev_rx_weight;
extern int dev_tx_weight;
extern int gro_normal_batch;
bool netdev_has_upper_dev(struct net_device *dev, struct net_device *upper_dev);
struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,