[Cake] Possible BUG - parent backlog incorrectly updated in case of NET_XMIT_CN

[Dave Taht]

Eric:

Quick side question (from trying to understand the qdisc locking fixes
you recently landed in net-next)

In the sqm-scripts, we are usually in a position where we are doing
both inbound and outbound rate limiting (htb + fq_codel or cake). We
typically run out of cpu or have mis-behavior on the inbound side, and
the cpu bottleneck appears to be in ksoftirqd.

A) In my failing to make sense of all the dialog around these patches
( https://lwn.net/Articles/687617/  ), it sounds like this (inbound
and outbound) processing are still locked to a single thread,
essentially?

B) But you have eliminated lot of overhead in basic qdisc processing
to much cpu benefit and we should consider backporting these changes
to lede/openwrt (4.4)?