[PATCH 3.12 23/83] pkt_sched: fq: change classification of control packets

Greg Kroah-Hartman
2013-12-06T22:38:37Z

From: Maciej Żenczykowski <maze@google.com>

[ Upstream commit 2abc2f070eb30ac8421554a5c32229f8332c6206 ]

Initial sch_fq implementation copied code from pfifo_fast to classify
a packet as a high prio packet.

This clashes with setups using PRIO with say 7 bands, as one of the
band could be incorrectly (mis)classified by FQ.

Packets would be queued in the 'internal' queue, and no pacing ever
happen for this special queue.

Fixes: afe4fd062416 ("pkt_sched: fq: Fair Queue packet scheduler")
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/sched/sch_fq.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)

--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -209,21 +209,15 @@ static void fq_gc(struct fq_sched_data *
}
}

-static const u8 prio2band[TC_PRIO_MAX + 1] = {
- 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1
-};
-
static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q)
{
struct rb_node **p, *parent;
struct sock *sk = skb->sk;
struct rb_root *root;
struct fq_flow *f;
- int band;

/* warning: no starvation prevention... */
- band = prio2band[skb->priority & TC_PRIO_MAX];
- if (unlikely(band == 0))
+ if (unlikely((skb->priority & TC_PRIO_MAX) == TC_PRIO_CONTROL))
return &q->internal;

if (unlikely(!sk)) {