mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

rxrpc: Send an ACK after every few DATA packets we receive 

Send an ACK if we haven't sent one for the last two packets we've received.
This keeps the other end apprised of where we've got to - which is
important if they're doing slow-start.

We do this in recvmsg so that we can dispatch a packet directly without the
need to wake up the background thread.

This should possibly be made configurable in future.

Signed-off-by: David Howells <dhowells@redhat.com>
This commit is contained in:
David Howells 2016-09-24 18:05:26 +01:00
parent c6a77ff82f
commit 805b21b929
4 changed files with 33 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
net/rxrpc/ar-internal.h
View File

@ -533,6 +533,8 @@ struct rxrpc_call {
u16 ackr_skew; /* skew on packet being ACK'd */
rxrpc_serial_t ackr_serial; /* serial of packet being ACK'd */
rxrpc_seq_t ackr_prev_seq; /* previous sequence number received */
rxrpc_seq_t ackr_consumed; /* Highest packet shown consumed */
rxrpc_seq_t ackr_seen; /* Highest packet shown seen */
rxrpc_serial_t ackr_ping; /* Last ping sent */
ktime_t ackr_ping_time; /* Time last ping sent */
@ -695,6 +697,7 @@ enum rxrpc_propose_ack_trace {
rxrpc_propose_ack_respond_to_ack,
rxrpc_propose_ack_respond_to_ping,
rxrpc_propose_ack_retry_tx,
rxrpc_propose_ack_rotate_rx,
rxrpc_propose_ack_terminal_ack,
rxrpc_propose_ack__nr_trace
};

1
net/rxrpc/misc.c
View File

@ -202,6 +202,7 @@ const char rxrpc_propose_ack_traces[rxrpc_propose_ack__nr_trace][8] = {
[rxrpc_propose_ack_respond_to_ack] = "Rsp2Ack",
[rxrpc_propose_ack_respond_to_ping] = "Rsp2Png",
[rxrpc_propose_ack_retry_tx] = "RetryTx",
[rxrpc_propose_ack_rotate_rx] = "RxAck ",
[rxrpc_propose_ack_terminal_ack] = "ClTerm ",
};

25
net/rxrpc/output.c
View File

@ -36,7 +36,9 @@ struct rxrpc_pkt_buffer {
* Fill out an ACK packet.
*/
static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
struct rxrpc_pkt_buffer *pkt)
struct rxrpc_pkt_buffer *pkt,
rxrpc_seq_t *_hard_ack,
rxrpc_seq_t *_top)
{
rxrpc_serial_t serial;
rxrpc_seq_t hard_ack, top, seq;
@ -48,6 +50,8 @@ static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
serial = call->ackr_serial;
hard_ack = READ_ONCE(call->rx_hard_ack);
top = smp_load_acquire(&call->rx_top);
*_hard_ack = hard_ack;
*_top = top;
pkt->ack.bufferSpace = htons(8);
pkt->ack.maxSkew = htons(call->ackr_skew);
@ -96,6 +100,7 @@ int rxrpc_send_call_packet(struct rxrpc_call *call, u8 type)
struct msghdr msg;
struct kvec iov[2];
rxrpc_serial_t serial;
rxrpc_seq_t hard_ack, top;
size_t len, n;
bool ping = false;
int ioc, ret;
@ -146,7 +151,7 @@ int rxrpc_send_call_packet(struct rxrpc_call *call, u8 type)
goto out;
}
ping = (call->ackr_reason == RXRPC_ACK_PING);
n = rxrpc_fill_out_ack(call, pkt);
n = rxrpc_fill_out_ack(call, pkt, &hard_ack, &top);
call->ackr_reason = 0;
spin_unlock_bh(&call->lock);
@ -203,18 +208,22 @@ int rxrpc_send_call_packet(struct rxrpc_call *call, u8 type)
if (ping)
call->ackr_ping_time = ktime_get_real();
if (ret < 0 && call->state < RXRPC_CALL_COMPLETE) {
switch (type) {
case RXRPC_PACKET_TYPE_ACK:
if (type == RXRPC_PACKET_TYPE_ACK &&
call->state < RXRPC_CALL_COMPLETE) {
if (ret < 0) {
clear_bit(RXRPC_CALL_PINGING, &call->flags);
rxrpc_propose_ACK(call, pkt->ack.reason,
ntohs(pkt->ack.maxSkew),
ntohl(pkt->ack.serial),
true, true,
rxrpc_propose_ack_retry_tx);
break;
case RXRPC_PACKET_TYPE_ABORT:
break;
} else {
spin_lock_bh(&call->lock);
if (after(hard_ack, call->ackr_consumed))
call->ackr_consumed = hard_ack;
if (after(top, call->ackr_seen))
call->ackr_seen = top;
spin_unlock_bh(&call->lock);
}
}

13
net/rxrpc/recvmsg.c
View File

@ -201,8 +201,19 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
_debug("%u,%u,%02x", hard_ack, top, flags);
trace_rxrpc_receive(call, rxrpc_receive_rotate, serial, hard_ack);
if (flags & RXRPC_LAST_PACKET)
if (flags & RXRPC_LAST_PACKET) {
rxrpc_end_rx_phase(call);
} else {
/* Check to see if there's an ACK that needs sending. */
if (after_eq(hard_ack, call->ackr_consumed + 2) ||
after_eq(top, call->ackr_seen + 2) ||
(hard_ack == top && after(hard_ack, call->ackr_consumed)))
rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, 0, serial,
true, false,
rxrpc_propose_ack_rotate_rx);
if (call->ackr_reason)
rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK);
}
}
/*