tree 9c0f004d07c1fe3314b155695a93f2de51a315c6
parent 35c55c9877f8de0ab129fa1a309271d0ecc868b9
author Eric Dumazet <edumazet@google.com> 1465874510 -0700
committer David S. Miller <davem@davemloft.net> 1466024914 -0700

net_sched: add the ability to defer skb freeing

qdisc are changed under RTNL protection and often
while blocking BH and root qdisc spinlock.

When lots of skbs need to be dropped, we free
them under these locks causing TX/RX freezes,
and more generally latency spikes.

This commit adds rtnl_kfree_skbs(), used to queue
skbs for deferred freeing.

Actual freeing happens right after RTNL is released,
with appropriate scheduling points.

rtnl_qdisc_drop() can also be used in place
of disc_drop() when RTNL is held.

qdisc_reset_queue() and __qdisc_reset_queue() get
the new behavior, so standard qdiscs like pfifo, pfifo_fast...
have their ->reset() method automatically handled.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>