diff options
| author | Patrick McHardy <kaber@trash.net> | 2008-11-24 15:46:08 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-11-24 15:46:08 -0800 |
| commit | 3f0947c3ffaed33c1c38b79e4b17f75ba072d3e9 (patch) | |
| tree | aabc1d3fadbfbfb97b2fe56884fad70197e50d47 | |
| parent | 4b40eed73e3787d60160beed1352ceadd24f6be1 (diff) | |
pkt_sched: sch_drr: fix drr_dequeue loop()
Jarek Poplawski points out:
If all child qdiscs of sch_drr are non-work-conserving (e.g. sch_tbf)
drr_dequeue() will busy-loop waiting for skbs instead of leaving the
job for a watchdog. Checking for list_empty() in each loop isn't
necessary either, because this can never be true except the first time.
Using non-work-conserving qdiscs as children of DRR makes no sense,
simply bail out in that case.
Reported-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/sched/sch_drr.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c index 37e6ab99bbea..e7a7e87b141a 100644 --- a/net/sched/sch_drr.c +++ b/net/sched/sch_drr.c @@ -373,11 +373,13 @@ static struct sk_buff *drr_dequeue(struct Qdisc *sch) struct sk_buff *skb; unsigned int len; - while (!list_empty(&q->active)) { + if (list_empty(&q->active)) + goto out; + while (1) { cl = list_first_entry(&q->active, struct drr_class, alist); skb = cl->qdisc->ops->peek(cl->qdisc); if (skb == NULL) - goto skip; + goto out; len = qdisc_pkt_len(skb); if (len <= cl->deficit) { @@ -390,9 +392,9 @@ static struct sk_buff *drr_dequeue(struct Qdisc *sch) } cl->deficit += cl->quantum; -skip: list_move_tail(&cl->alist, &q->active); } +out: return NULL; } |