net: add low latency socket poll

Adds an ndo_ll_poll method and the code that supports it.
This method can be used by low latency applications to busy-poll
Ethernet device queues directly from the socket code.
sysctl_net_ll_poll controls how many microseconds to poll.
Default is zero (disabled).
Individual protocol support will be added by subsequent patches.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Tested-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index 66772cf8c3c5..ac8e1818380c 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -229,6 +229,7 @@ struct cg_proto;
   *     @sk_omem_alloc: "o" is "option" or "other"
   *     @sk_wmem_queued: persistent queue size
   *     @sk_forward_alloc: space allocated forward
+  *     @sk_napi_id: id of the last napi context to receive data for sk
   *     @sk_allocation: allocation mode
   *     @sk_sndbuf: size of send buffer in bytes
   *     @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
@@ -325,6 +326,9 @@ struct sock {
 #ifdef CONFIG_RPS
         __u32                   sk_rxhash;
 #endif
+#ifdef CONFIG_NET_LL_RX_POLL
+        unsigned int            sk_napi_id;
+#endif
         atomic_t                sk_drops;
         int                     sk_rcvbuf;