net: rename low latency sockets functions to busy poll

Rename functions in include/net/ll_poll.h to busy wait.
Clarify documentation about expected power use increase.
Rename POLL_LL to POLL_BUSY_LOOP.
Add need_resched() testing to poll/select busy loops.

Note, that in select and poll can_busy_poll is dynamic and is
updated continuously to reflect the existence of supported
sockets with valid queue information.

Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 3 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 46ed9afd1f5e..15cbfa94bd8e 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1554,9 +1554,9 @@ 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);
+        if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) &&
+            (sk->sk_state == TCP_ESTABLISHED))
+                sk_busy_loop(sk, nonblock);
 
         lock_sock(sk);