David Howells 5a2c5a5b08 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
2023-02-07 23:11:21 +00:00
..
2023-01-31 16:38:35 +00:00
2023-01-30 14:13:29 +00:00
2023-02-07 23:11:21 +00:00
2023-01-31 16:38:35 +00:00
2023-01-31 16:38:35 +00:00
2023-01-31 16:38:35 +00:00
2023-02-07 23:11:21 +00:00
2023-01-07 09:30:26 +00:00