sched: KISTLite should set an upper limit to write on the outbuf
Right now, for the
KISTLite scheduler, the write limit on the outbuf for a channel is set to
INT_MAX. This is crazy high and will bloat the outbuf if the channel is struggling to send out data on the wire or the socket is stuck.
Vanilla scheduler uses the
num_cells_writeable() method to limit the amount it puts on the outbuf which is 32KB maximum.
KIST uses the kernel information for this limit.
This is very important that we actually put a limit in the outbuf because it keeps the cells in the circuit queue and that is handled by our OOM in case of memory pressure.
I suggest we simply use the
channel_num_cells_writeable() for the upper limit when KISTLite is used.