tree 28ab84ef30e3c6317dea99f4826e1a31d38795b2
parent ae8509c420122866344bde1241e31858d0aa2fbc
author Ying Xue <ying.xue@windriver.com> 1371480888 -0400
committer David S. Miller <davem@davemloft.net> 1371509581 -0700

tipc: enhance priority of link protocol packet

pfifo_fast is set as default traffic class queueing discipline. This
queue has three so called "bands". Within each band, FIFO rules apply.
However, as long as there are packets waiting in band 0, band 1 won't
be processed.

Now all kind of TIPC type packet priorities are never set, that is,
their priorities are 0, so they are mapped to band 1 of pfifo_fast
qdisc. But, especially during link congestion, if link protocol packet
can be sent out as earlier as possible than other type of packets so
that protocol packet can arrive at peer endpoint in time, the peer
will timely reset its link timeout timer to keep the link alive.
So enhancing the priority of link protocol packets can meet the
specific demand to avoid unnecessary link reset due to a transient
link congestion.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>