rxrpc: Reduce the number of ACK-Requests sent
Reduce the number of ACK-Requests we set on DATA packets that we're sending
to reduce network traffic. We set the flag on odd-numbered DATA packets to
start off the RTT cache until we have at least three entries in it and then
probe once per second thereafter to keep it topped up.
This could be made tunable in future.
Note that from this point, the RXRPC_REQUEST_ACK flag is set on DATA
packets as we transmit them and not stored statically in the sk_buff.
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 1c4597b..b13754a 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -255,6 +255,7 @@
/* calculated RTT cache */
#define RXRPC_RTT_CACHE_SIZE 32
+ ktime_t rtt_last_req; /* Time of last RTT request */
u64 rtt; /* Current RTT estimate (in nS) */
u64 rtt_sum; /* Sum of cache contents */
u64 rtt_cache[RXRPC_RTT_CACHE_SIZE]; /* Determined RTT cache */