diff options
| author | David Howells <dhowells@redhat.com> | 2022-11-11 13:47:35 +0000 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2022-12-01 13:36:43 +0000 |
| commit | 5086d9a9dfec4866806da303115489b0606decb7 (patch) | |
| tree | 286a9b9c8cf80a3e853baa20cdf4bac9cc425718 /net/rxrpc/ar-internal.h | |
| parent | 32cf8edb079a6a687a2b5dba39a813a0bbd0ddf9 (diff) | |
rxrpc: Move the cwnd degradation after transmitting packets
When we've gone for >1RTT without transmitting a packet, we should reduce
the ssthresh and cut the cwnd by half (as suggested in RFC2861 sec 3.1).
However, we may receive ACK packets in a batch and the first of these may
cut the cwnd, preventing further transmission, and each subsequent one cuts
the cwnd yet further, reducing it to the floor and killing performance.
Fix this by moving the cwnd reset to after doing the transmission and
resetting the base time such that we don't cut the cwnd by half again for
at least another RTT.
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/ar-internal.h')
| -rw-r--r-- | net/rxrpc/ar-internal.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h index 6cfe366ee224..785cd0dd1eea 100644 --- a/net/rxrpc/ar-internal.h +++ b/net/rxrpc/ar-internal.h @@ -666,6 +666,7 @@ struct rxrpc_call { * packets) rather than bytes. */ #define RXRPC_TX_SMSS RXRPC_JUMBO_DATALEN +#define RXRPC_MIN_CWND (RXRPC_TX_SMSS > 2190 ? 2 : RXRPC_TX_SMSS > 1095 ? 3 : 4) u8 cong_cwnd; /* Congestion window size */ u8 cong_extra; /* Extra to send for congestion management */ u8 cong_ssthresh; /* Slow-start threshold */ @@ -953,6 +954,7 @@ void rxrpc_unpublish_service_conn(struct rxrpc_connection *); /* * input.c */ +void rxrpc_congestion_degrade(struct rxrpc_call *); void rxrpc_input_call_packet(struct rxrpc_call *, struct sk_buff *); void rxrpc_implicit_end_call(struct rxrpc_call *, struct sk_buff *); |