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>
This commit is contained in:
Eliezer Tamir 2013-06-10 11:40:00 +03:00 committed by David S. Miller
parent 0602129286
commit a5b50476f7
3 changed files with 14 additions and 2 deletions

View file

@ -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 @@ struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned int flags,
}
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)

View file

@ -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 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
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

View file

@ -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 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
*/
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