Commit d30e383b authored by Eliezer Tamir's avatar Eliezer Tamir Committed by David S. Miller
Browse files

tcp: add low latency socket poll support. 



Adds low latency socket poll support for TCP.
In tcp_v[46]_rcv() add a call to sk_mark_ll() to copy the napi_id
from the skb to the sk.
In tcp_recvmsg(), when there is no data in the socket we busy-poll.
This is a good example of how to add busy-poll support to more protocols.

Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: default avatarJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: default avatarEliezer Tamir <eliezer.tamir@linux.intel.com>
Acked-by: default avatarEric Dumazet <edumazet@google.com>
Tested-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a5b50476

net/ipv4/tcp.c

+5 −0
Original line number Diff line number Diff line
@@ -279,6 +279,7 @@ 


#include <asm/uaccess.h>

#include <asm/ioctls.h>

#include <net/ll_poll.h>



int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
@@ -1553,6 +1554,10 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 
	struct sk_buff *skb;

	u32 urg_hole = 0;



	if (sk_valid_ll(sk) && skb_queue_empty(&sk->sk_receive_queue)

	    && (sk->sk_state == TCP_ESTABLISHED))

		sk_poll_ll(sk, nonblock);



	lock_sock(sk);



	err = -ENOTCONN;

net/ipv4/tcp_ipv4.c

+2 −0
Original line number Diff line number Diff line
@@ -75,6 +75,7 @@ 
#include <net/netdma.h>

#include <net/secure_seq.h>

#include <net/tcp_memcontrol.h>

#include <net/ll_poll.h>



#include <linux/inet.h>

#include <linux/ipv6.h>
@@ -1993,6 +1994,7 @@ process: 
	if (sk_filter(sk, skb))

		goto discard_and_relse;



	sk_mark_ll(sk, skb);

	skb->dev = NULL;



	bh_lock_sock_nested(sk);

net/ipv6/tcp_ipv6.c

+2 −0
Original line number Diff line number Diff line
@@ -63,6 +63,7 @@ 
#include <net/inet_common.h>

#include <net/secure_seq.h>

#include <net/tcp_memcontrol.h>

#include <net/ll_poll.h>



#include <asm/uaccess.h>
@@ -1498,6 +1499,7 @@ process: 
	if (sk_filter(sk, skb))

		goto discard_and_relse;



	sk_mark_ll(sk, skb);

	skb->dev = NULL;



	bh_lock_sock_nested(sk);

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