This set of patches implements the RxRPC slow-start feature for AF_RXRPC to improve performance and handling of occasional packet loss. This is more or less the same as TCP slow start [RFC 5681]. Firstly, there are some ACK generation improvements:
(1) Send ACKs regularly to apprise the peer of our state so that they can do congestion management of their own. (2) Send an ACK when we fill in a hole in the buffer so that the peer can find out that we did this thus forestalling retransmission. (3) Note the final DATA packet's serial number in the final ACK for correlation purposes. and a couple of bug fixes: (4) Reinitialise the ACK state and clear the ACK and resend timers upon entering the client reply reception phase to kill off any pending probe ACKs. (5) Delay the resend timer to allow for nsec->jiffies conversion errors. and then there's the slow-start pieces: (6) Summarise an ACK. (7) Schedule a PING or IDLE ACK if the reply to a client call is overdue to try and find out what happened to it. (8) Implement the slow start feature. The patches can be found here also: http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=rxrpc-rewrite Tagged thusly: git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git rxrpc-rewrite-20160924 David --- David Howells (8): rxrpc: Send an ACK after every few DATA packets we receive rxrpc: Send an immediate ACK if we fill in a hole rxrpc: Include the last reply DATA serial number in the final ACK rxrpc: Reinitialise the call ACK and timer state for client reply phase rxrpc: Delay the resend timer to allow for nsec->jiffies conv error rxrpc: Generate a summary of the ACK state for later use rxrpc: Schedule an ACK if the reply to a client call appears overdue rxrpc: Implement slow-start include/trace/events/rxrpc.h | 45 ++++++++ net/rxrpc/ar-internal.h | 71 ++++++++++++ net/rxrpc/call_event.c | 47 +++++++- net/rxrpc/call_object.c | 13 ++ net/rxrpc/conn_event.c | 1 net/rxrpc/input.c | 241 +++++++++++++++++++++++++++++++++++++++--- net/rxrpc/misc.c | 23 ++++ net/rxrpc/output.c | 34 ++++-- net/rxrpc/recvmsg.c | 19 +++ net/rxrpc/sendmsg.c | 7 + 10 files changed, 463 insertions(+), 38 deletions(-)