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authorDavid Howells <dhowells@redhat.com>2014-02-14 20:05:32 +0000
committerDavid Howells <dhowells@redhat.com>2014-02-26 17:25:07 +0000
commite8388eb10371745627d1e538e018cb10ded86aa7 (patch)
tree4adf9238ecba8a33d74fdbaf5c1b212b5f5324ad
parent817913d8cd7627d9303bce97c3c339ceb0f8e199 (diff)
downloadlinux-e8388eb10371745627d1e538e018cb10ded86aa7.tar.bz2
af_rxrpc: Request an ACK for every alternate DATA packet
Set the RxRPC header flag to request an ACK packet for every odd-numbered DATA packet unless it's the last one (which implicitly requests an ACK anyway). This is similar to how librx appears to work. If we don't do this, we'll send out a full window of packets and then just sit there until the other side gets bored and sends an ACK to indicate that it's been idle for a while and has received no new packets. Requesting a lot of ACKs shouldn't be a problem as ACKs should be merged when possible. As AF_RXRPC currently works, it will schedule an ACK to be generated upon receipt of a DATA packet with the ACK-request packet set - and in the time taken to schedule this in a work queue, several other packets are likely to arrive and then all get ACK'd together. Signed-off-by: David Howells <dhowells@redhat.com>
-rw-r--r--net/rxrpc/ar-output.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/net/rxrpc/ar-output.c b/net/rxrpc/ar-output.c
index 4814d882bcb4..0b4b9a79f5ab 100644
--- a/net/rxrpc/ar-output.c
+++ b/net/rxrpc/ar-output.c
@@ -669,6 +669,7 @@ static int rxrpc_send_data(struct kiocb *iocb,
/* add the packet to the send queue if it's now full */
if (sp->remain <= 0 || (segment == 0 && !more)) {
struct rxrpc_connection *conn = call->conn;
+ uint32_t seq;
size_t pad;
/* pad out if we're using security */
@@ -681,11 +682,12 @@ static int rxrpc_send_data(struct kiocb *iocb,
memset(skb_put(skb, pad), 0, pad);
}
+ seq = atomic_inc_return(&call->sequence);
+
sp->hdr.epoch = conn->epoch;
sp->hdr.cid = call->cid;
sp->hdr.callNumber = call->call_id;
- sp->hdr.seq =
- htonl(atomic_inc_return(&call->sequence));
+ sp->hdr.seq = htonl(seq);
sp->hdr.serial =
htonl(atomic_inc_return(&conn->serial));
sp->hdr.type = RXRPC_PACKET_TYPE_DATA;
@@ -700,6 +702,8 @@ static int rxrpc_send_data(struct kiocb *iocb,
else if (CIRC_SPACE(call->acks_head, call->acks_tail,
call->acks_winsz) > 1)
sp->hdr.flags |= RXRPC_MORE_PACKETS;
+ if (more && seq & 1)
+ sp->hdr.flags |= RXRPC_REQUEST_ACK;
ret = rxrpc_secure_packet(
call, skb, skb->mark,