udp: add low latency socket poll support
Add upport for busy-polling on UDP sockets.
In __udp[46]_lib_rcv add a call to sk_mark_ll() to copy the napi_id
from the skb into the sk.
This is done at the earliest possible moment, right after we identify
which socket this skb is for.
In __skb_recv_datagram When there is no data and the user
tries to read we busy poll.
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>
diff --git a/net/core/datagram.c b/net/core/datagram.c
index b71423d..9cbaba98 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -56,6 +56,7 @@
#include <net/sock.h>
#include <net/tcp_states.h>
#include <trace/events/skb.h>
+#include <net/ll_poll.h>
/*
* Is a socket 'connection oriented' ?
@@ -207,6 +208,9 @@
}
spin_unlock_irqrestore(&queue->lock, cpu_flags);
+ if (sk_valid_ll(sk) && sk_poll_ll(sk, flags & MSG_DONTWAIT))
+ continue;
+
/* User doesn't want to wait */
error = -EAGAIN;
if (!timeo)
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index c7338ec..2955b25 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -109,6 +109,7 @@
#include <trace/events/udp.h>
#include <linux/static_key.h>
#include <trace/events/skb.h>
+#include <net/ll_poll.h>
#include "udp_impl.h"
struct udp_table udp_table __read_mostly;
@@ -1709,7 +1710,10 @@
sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
if (sk != NULL) {
- int ret = udp_queue_rcv_skb(sk, skb);
+ int ret;
+
+ sk_mark_ll(sk, skb);
+ ret = udp_queue_rcv_skb(sk, skb);
sock_put(sk);
/* a return value > 0 means to resubmit the input, but
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index b580853..f77e34c 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -46,6 +46,7 @@
#include <net/ip6_checksum.h>
#include <net/xfrm.h>
#include <net/inet6_hashtables.h>
+#include <net/ll_poll.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
@@ -841,7 +842,10 @@
*/
sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
if (sk != NULL) {
- int ret = udpv6_queue_rcv_skb(sk, skb);
+ int ret;
+
+ sk_mark_ll(sk, skb);
+ ret = udpv6_queue_rcv_skb(sk, skb);
sock_put(sk);
/* a return value > 0 means to resubmit the input, but