From: David Howells <dhowells@redhat.com>
Date: Sat, 24 Sep 2016 17:05:27 +0000 (+0100)
Subject: rxrpc: Send an immediate ACK if we fill in a hole
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a7056c5ba67ee6a956b42cf9ff9ba3a6a0bd9794;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

rxrpc: Send an immediate ACK if we fill in a hole

Send an immediate ACK if we fill in a hole in the buffer left by an
out-of-sequence packet.  This may allow the congestion management in the peer
to avoid a retransmission if packets got reordered on the wire.

Signed-off-by: David Howells <dhowells@redhat.com>
---

diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 349698d87ad1..757c16f033a0 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -331,8 +331,16 @@ next_subpacket:
 	call->rxtx_annotations[ix] = annotation;
 	smp_wmb();
 	call->rxtx_buffer[ix] = skb;
-	if (after(seq, call->rx_top))
+	if (after(seq, call->rx_top)) {
 		smp_store_release(&call->rx_top, seq);
+	} else if (before(seq, call->rx_top)) {
+		/* Send an immediate ACK if we fill in a hole */
+		if (!ack) {
+			ack = RXRPC_ACK_DELAY;
+			ack_serial = serial;
+		}
+		immediate_ack = true;
+	}
 	if (flags & RXRPC_LAST_PACKET) {
 		set_bit(RXRPC_CALL_RX_LAST, &call->flags);
 		trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq);