net: sched: avoid costly atomic operation in fq_dequeue()
authorEric Dumazet <edumazet@google.com>
Sat, 4 Oct 2014 17:11:31 +0000 (10:11 -0700)
committerDavid S. Miller <davem@davemloft.net>
Mon, 6 Oct 2014 04:55:10 +0000 (00:55 -0400)
commitf2600cf02b5b59aaee082c3485b7f01fc7f7b70c
treef38d692c3f706ead3d0cfd77b216fbd629a22964
parent681d2421e1135b95f5cd9d16fe10eac7f570a9f2
net: sched: avoid costly atomic operation in fq_dequeue()

Standard qdisc API to setup a timer implies an atomic operation on every
packet dequeue : qdisc_unthrottled()

It turns out this is not really needed for FQ, as FQ has no concept of
global qdisc throttling, being a qdisc handling many different flows,
some of them can be throttled, while others are not.

Fix is straightforward : add a 'bool throttle' to
qdisc_watchdog_schedule_ns(), and remove calls to qdisc_unthrottled()
in sch_fq.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/net/pkt_sched.h
net/sched/sch_api.c
net/sched/sch_fq.c
net/sched/sch_tbf.c