]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/commit - net/sched/sch_fifo.c
net_sched: drop packets after root qdisc lock is released
authorEric Dumazet <edumazet@google.com>
Wed, 22 Jun 2016 06:16:49 +0000 (23:16 -0700)
committerDavid S. Miller <davem@davemloft.net>
Sat, 25 Jun 2016 16:19:35 +0000 (12:19 -0400)
commit520ac30f45519b0a82dd92117c181d1d6144677b
treea3189ae1ab3b5be6213716e42ddaec082578e774
parent36195d869e4b1dbf81bafa3a31bb095a3c013bdd
net_sched: drop packets after root qdisc lock is released

Qdisc performance suffers when packets are dropped at enqueue()
time because drops (kfree_skb()) are done while qdisc lock is held,
delaying a dequeue() draining the queue.

Nominal throughput can be reduced by 50 % when this happens,
at a time we would like the dequeue() to proceed as fast as possible.

Even FQ is vulnerable to this problem, while one of FQ goals was
to provide some flow isolation.

This patch adds a 'struct sk_buff **to_free' parameter to all
qdisc->enqueue(), and in qdisc_drop() helper.

I measured a performance increase of up to 12 %, but this patch
is a prereq so that future batches in enqueue() can fly.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
28 files changed:
include/net/sch_generic.h
net/core/dev.c
net/sched/sch_atm.c
net/sched/sch_blackhole.c
net/sched/sch_cbq.c
net/sched/sch_choke.c
net/sched/sch_codel.c
net/sched/sch_drr.c
net/sched/sch_dsmark.c
net/sched/sch_fifo.c
net/sched/sch_fq.c
net/sched/sch_fq_codel.c
net/sched/sch_generic.c
net/sched/sch_gred.c
net/sched/sch_hfsc.c
net/sched/sch_hhf.c
net/sched/sch_htb.c
net/sched/sch_multiq.c
net/sched/sch_netem.c
net/sched/sch_pie.c
net/sched/sch_plug.c
net/sched/sch_prio.c
net/sched/sch_qfq.c
net/sched/sch_red.c
net/sched/sch_sfb.c
net/sched/sch_sfq.c
net/sched/sch_tbf.c
net/sched/sch_teql.c