From 5873c0834f8896aa9da338b941035a2f8b29e99b Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 7 Feb 2014 18:58:44 +0000 Subject: af_rxrpc: Add sysctls for configuring RxRPC parameters Add sysctls for configuring RxRPC protocol handling, specifically controls on delays before ack generation, the delay before resending a packet, the maximum lifetime of a call and the expiration times of calls, connections and transports that haven't been recently used. More info added in Documentation/networking/rxrpc.txt. Signed-off-by: David Howells --- Documentation/networking/rxrpc.txt | 62 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) (limited to 'Documentation/networking') diff --git a/Documentation/networking/rxrpc.txt b/Documentation/networking/rxrpc.txt index b89bc82eed46..aa08d2625f05 100644 --- a/Documentation/networking/rxrpc.txt +++ b/Documentation/networking/rxrpc.txt @@ -27,6 +27,8 @@ Contents of this document: (*) AF_RXRPC kernel interface. + (*) Configurable parameters. + ======== OVERVIEW @@ -864,3 +866,63 @@ The kernel interface functions are as follows: This is used to allocate a null RxRPC key that can be used to indicate anonymous security for a particular domain. + + +======================= +CONFIGURABLE PARAMETERS +======================= + +The RxRPC protocol driver has a number of configurable parameters that can be +adjusted through sysctls in /proc/net/rxrpc/: + + (*) req_ack_delay + + The amount of time in milliseconds after receiving a packet with the + request-ack flag set before we honour the flag and actually send the + requested ack. + + Usually the other side won't stop sending packets until the advertised + reception window is full (to a maximum of 255 packets), so delaying the + ACK permits several packets to be ACK'd in one go. + + (*) soft_ack_delay + + The amount of time in milliseconds after receiving a new packet before we + generate a soft-ACK to tell the sender that it doesn't need to resend. + + (*) idle_ack_delay + + The amount of time in milliseconds after all the packets currently in the + received queue have been consumed before we generate a hard-ACK to tell + the sender it can free its buffers, assuming no other reason occurs that + we would send an ACK. + + (*) resend_timeout + + The amount of time in milliseconds after transmitting a packet before we + transmit it again, assuming no ACK is received from the receiver telling + us they got it. + + (*) max_call_lifetime + + The maximum amount of time in seconds that a call may be in progress + before we preemptively kill it. + + (*) dead_call_expiry + + The amount of time in seconds before we remove a dead call from the call + list. Dead calls are kept around for a little while for the purpose of + repeating ACK and ABORT packets. + + (*) connection_expiry + + The amount of time in seconds after a connection was last used before we + remove it from the connection list. Whilst a connection is in existence, + it serves as a placeholder for negotiated security; when it is deleted, + the security must be renegotiated. + + (*) transport_expiry + + The amount of time in seconds after a transport was last used before we + remove it from the transport list. Whilst a transport is in existence, it + serves to anchor the peer data and keeps the connection ID counter. -- cgit From 817913d8cd7627d9303bce97c3c339ceb0f8e199 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 7 Feb 2014 18:10:30 +0000 Subject: af_rxrpc: Expose more RxRPC parameters via sysctls Expose RxRPC parameters via sysctls to control the Rx window size, the Rx MTU maximum size and the number of packets that can be glued into a jumbo packet. More info added to Documentation/networking/rxrpc.txt. Signed-off-by: David Howells --- Documentation/networking/rxrpc.txt | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'Documentation/networking') diff --git a/Documentation/networking/rxrpc.txt b/Documentation/networking/rxrpc.txt index aa08d2625f05..16a924c486bf 100644 --- a/Documentation/networking/rxrpc.txt +++ b/Documentation/networking/rxrpc.txt @@ -926,3 +926,22 @@ adjusted through sysctls in /proc/net/rxrpc/: The amount of time in seconds after a transport was last used before we remove it from the transport list. Whilst a transport is in existence, it serves to anchor the peer data and keeps the connection ID counter. + + (*) rxrpc_rx_window_size + + The size of the receive window in packets. This is the maximum number of + unconsumed received packets we're willing to hold in memory for any + particular call. + + (*) rxrpc_rx_mtu + + The maximum packet MTU size that we're willing to receive in bytes. This + indicates to the peer whether we're willing to accept jumbo packets. + + (*) rxrpc_rx_jumbo_max + + The maximum number of packets that we're willing to accept in a jumbo + packet. Non-terminal packets in a jumbo packet must contain a four byte + header plus exactly 1412 bytes of data. The terminal packet must contain + a four byte header plus any amount of data. In any event, a jumbo packet + may not exceed rxrpc_rx_mtu in size. -- cgit