net: add socket option for low latency polling
adds a socket option for low latency polling.
This allows overriding the global sysctl value with a per-socket one.
Unexport sysctl_net_ll_poll since for now it's not needed in modules.
Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ll_poll.h b/include/net/ll_poll.h
index 6930cbd..fcc7c36 100644
--- a/include/net/ll_poll.h
+++ b/include/net/ll_poll.h
@@ -39,12 +39,12 @@
/* we can use sched_clock() because we don't care much about precision
* we only care that the average is bounded
*/
-static inline u64 ll_end_time(void)
+static inline u64 ll_end_time(struct sock *sk)
{
- u64 end_time = ACCESS_ONCE(sysctl_net_ll_poll);
+ u64 end_time = ACCESS_ONCE(sk->sk_ll_usec);
/* we don't mind a ~2.5% imprecision
- * sysctl_net_ll_poll is a u_int so this can't overflow
+ * sk->sk_ll_usec is a u_int so this can't overflow
*/
end_time = (end_time << 10) + sched_clock();
@@ -53,7 +53,7 @@
static inline bool sk_valid_ll(struct sock *sk)
{
- return sysctl_net_ll_poll && sk->sk_napi_id &&
+ return sk->sk_ll_usec && sk->sk_napi_id &&
!need_resched() && !signal_pending(current);
}
@@ -65,7 +65,7 @@
static inline bool sk_poll_ll(struct sock *sk, int nonblock)
{
const struct net_device_ops *ops;
- u64 end_time = ll_end_time();
+ u64 end_time = ll_end_time(sk);
struct napi_struct *napi;
int rc = false;
@@ -118,7 +118,7 @@
#else /* CONFIG_NET_LL_RX_POLL */
-static inline u64 ll_end_time(void)
+static inline u64 ll_end_time(struct sock *sk)
{
return 0;
}
diff --git a/include/net/sock.h b/include/net/sock.h
index ac8e181..21db792 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -230,6 +230,7 @@
* @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_ll_usec: usecs to busypoll when there is no data
* @sk_allocation: allocation mode
* @sk_sndbuf: size of send buffer in bytes
* @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
@@ -328,6 +329,7 @@
#endif
#ifdef CONFIG_NET_LL_RX_POLL
unsigned int sk_napi_id;
+ unsigned int sk_ll_usec;
#endif
atomic_t sk_drops;
int sk_rcvbuf;