* [PATCH net] pkt_sched: fq: avoid hang when quantum 0
@ 2015-02-03 16:49 Kenneth Klette Jonassen
2015-02-03 17:46 ` Eric Dumazet
0 siblings, 1 reply; 3+ messages in thread
From: Kenneth Klette Jonassen @ 2015-02-03 16:49 UTC (permalink / raw)
To: netdev; +Cc: Kenneth Klette Jonassen
Configuring fq with quantum 0 hangs the system, presumably because of a
non-interruptible infinite loop. Either way quantum 0 does not make sense.
Reproduce with:
sudo tc qdisc add dev lo root fq quantum 0 initial_quantum 0
ping 127.0.0.1
Signed-off-by: Kenneth Klette Jonassen <kennetkl@ifi.uio.no>
---
net/sched/sch_fq.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c
index 2a50f5c..313794b 100644
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -670,8 +670,14 @@ static int fq_change(struct Qdisc *sch, struct nlattr *opt)
if (tb[TCA_FQ_FLOW_PLIMIT])
q->flow_plimit = nla_get_u32(tb[TCA_FQ_FLOW_PLIMIT]);
- if (tb[TCA_FQ_QUANTUM])
- q->quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]);
+ if (tb[TCA_FQ_QUANTUM]) {
+ u32 quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]);
+
+ if (quantum > 0)
+ q->quantum = quantum;
+ else
+ err = -EINVAL;
+ }
if (tb[TCA_FQ_INITIAL_QUANTUM])
q->initial_quantum = nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM]);
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH net] pkt_sched: fq: avoid hang when quantum 0
2015-02-03 16:49 [PATCH net] pkt_sched: fq: avoid hang when quantum 0 Kenneth Klette Jonassen
@ 2015-02-03 17:46 ` Eric Dumazet
2015-02-05 4:08 ` David Miller
0 siblings, 1 reply; 3+ messages in thread
From: Eric Dumazet @ 2015-02-03 17:46 UTC (permalink / raw)
To: Kenneth Klette Jonassen; +Cc: netdev
On Tue, 2015-02-03 at 17:49 +0100, Kenneth Klette Jonassen wrote:
> Configuring fq with quantum 0 hangs the system, presumably because of a
> non-interruptible infinite loop. Either way quantum 0 does not make sense.
>
> Reproduce with:
> sudo tc qdisc add dev lo root fq quantum 0 initial_quantum 0
> ping 127.0.0.1
>
> Signed-off-by: Kenneth Klette Jonassen <kennetkl@ifi.uio.no>
> ---
Acked-by: Eric Dumazet <edumazet@google.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH net] pkt_sched: fq: avoid hang when quantum 0
2015-02-03 17:46 ` Eric Dumazet
@ 2015-02-05 4:08 ` David Miller
0 siblings, 0 replies; 3+ messages in thread
From: David Miller @ 2015-02-05 4:08 UTC (permalink / raw)
To: eric.dumazet; +Cc: kennetkl, netdev
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Tue, 03 Feb 2015 09:46:09 -0800
> On Tue, 2015-02-03 at 17:49 +0100, Kenneth Klette Jonassen wrote:
>> Configuring fq with quantum 0 hangs the system, presumably because of a
>> non-interruptible infinite loop. Either way quantum 0 does not make sense.
>>
>> Reproduce with:
>> sudo tc qdisc add dev lo root fq quantum 0 initial_quantum 0
>> ping 127.0.0.1
>>
>> Signed-off-by: Kenneth Klette Jonassen <kennetkl@ifi.uio.no>
>> ---
>
> Acked-by: Eric Dumazet <edumazet@google.com>
Applied, thanks.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2015-02-03 16:49 [PATCH net] pkt_sched: fq: avoid hang when quantum 0 Kenneth Klette Jonassen
2015-02-03 17:46 ` Eric Dumazet
2015-02-05 4:08 ` David Miller
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