diff options
| author | David Howells <dhowells@redhat.com> | 2023-01-31 22:40:18 +0100 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2023-02-08 00:11:21 +0100 |
| commit | 5a2c5a5b0829ef8bcb5d868145c1d8c1221c5637 (patch) | |
| tree | 441da5c8f36a3c989c34f698746e1a00ff993976 /net/rxrpc | |
| parent | rxrpc: Trace ack.rwind (diff) | |
| download | linux-5a2c5a5b0829ef8bcb5d868145c1d8c1221c5637.tar.xz linux-5a2c5a5b0829ef8bcb5d868145c1d8c1221c5637.zip | |
rxrpc: Reduce unnecessary ack transmission
rxrpc_recvmsg_data() schedules an ACK to be transmitted every time at least
two packets have been consumed and any time it runs out of data and would
return -EAGAIN to the caller. Both events may occur within a single loop,
however, and if the I/O thread is quick enough it may send duplicate ACKs.
The ACKs are sent to inform the peer that more space has been made in the
local Rx window, but the I/O thread is going to send an ACK every couple of
DATA packets anyway, so we end up sending a lot more ACKs than we really
need to.
So reduce the rate at which recvmsg() schedules ACKs, such that if the I/O
thread sends ACKs at its normal faster rate, recvmsg() won't actually
schedule ACKs until the Rx flow stops (call->rx_consumed is cleared any
time we transmit an ACK for that call, resetting the counter used by
recvmsg).
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Diffstat (limited to 'net/rxrpc')
| -rw-r--r-- | net/rxrpc/recvmsg.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c index 50d263a6359d..76eb2b9cd936 100644 --- a/net/rxrpc/recvmsg.c +++ b/net/rxrpc/recvmsg.c @@ -137,7 +137,7 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call) /* Check to see if there's an ACK that needs sending. */ acked = atomic_add_return(call->rx_consumed - old_consumed, &call->ackr_nr_consumed); - if (acked > 2 && + if (acked > 8 && !test_and_set_bit(RXRPC_CALL_RX_IS_IDLE, &call->flags)) rxrpc_poke_call(call, rxrpc_call_poke_idle); } |