On 23.05.19 12:20, Kurt Van Dijck wrote:
On do, 23 mei 2019 11:41:22 +0200, Oleksij Rempel wrote:
This patch series is a preparation and actual session queue support.
From now, we are able to use full available wmem of the socket and
queue all requests if it is needed. The stack will process
all queued requests in the FIFO order and notify user space application
about error or completion over the errqueue interface.
I don't understand why it is necessary to queue single messages into a
FIFO and notify user space later on?
I'm not sure I understand this question. What type of message is "single messages" in your
case?
1. Notification in user space are optional and should be enabled by application - there
are no necessity in it.
2. If we need to keep order of queued messages there is no way you can predict if user
space will put one or 100 messages in it, so every message go through the FIFO.
3. The feedback mechanism is provided for every type of message since it is possible to
drop complete queue, so we are still able to notify user space about doped or send messages.
Are you sure that different sockets still send asynchronous from each
other as long as TP/ETP is not involved?
Yes. It is per socket queue. First message in the queue are currently activated
independent of each other.
As soon as different sockets have same address and trying to start or queue a transfer
with conflicting type, address and direction, current stack implementation will
block/prevent second transfer to start.
The next step would be to implement dequeuing mechanism for conflicting transfers queued
in different sockets.
As usual, reviews and tests are welcome.
Oleksij Rempel (17):
j1939: store session type in to session and start to use it
j1939: transport: do not send packets from j1939_tp_send
j1939: transport: seed retry timeout for (E)TP sessions
j1939: pack simple messages in to a session
j1939: socket: use min_t where possible
j1939: transport: fix broken refcounting on j1939_xtp_rx_rts_current
error
j1939: move struct j1939_sock to the header file
j1939: transport: return proper error on skb underrun.
j1939: split j1939_tp_send
j1939: transport: cancel session on j1939_tp_txnext error
j1939: transport: abort not started session if requested
j1939: add session state
j1939: transport: better protect j1939_session_insert with lock
j1939: implement session queue
j1939: rename j1939_sk_send_multi to j1939_sk_send_loop
j1939: rename tp_sessionq to active_session_list
j1939: rename jsk_fifo to sk_session_queue_entry
net/can/j1939/j1939-priv.h | 78 +++++++-
net/can/j1939/main.c | 2 +
net/can/j1939/socket.c | 238 +++++++++++++----------
net/can/j1939/transport.c | 384 ++++++++++++++++++-------------------
4 files changed, 388 insertions(+), 314 deletions(-)
--
2.20.1
Kind regards,
Oleksij Rempel
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