Re: WARNING: CPU: 3 PID: 0 at net/sched/sch_hfsc.c:1388 hfsc_dequeue+0x319/0x350 [sch_hfsc]

On 18-03-15 08:48 PM, Cong Wang wrote:

On Wed, Mar 14, 2018 at 1:10 AM, Marco Berizzi [off-list ref] wrote:

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Il 9 marzo 2018 alle 0.14 Cong Wang [off-list ref] ha scritto:


On Thu, Mar 8, 2018 at 8:02 AM, Marco Berizzi [off-list ref] wrote:

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Marco Berizzi wrote:


Hello everyone,

Yesterday I got this error on a slackware linux 4.16-rc4 system
running as a traffic shaping gateway and netfilter nat.
The error has been arisen after a partial ISP network outage,
so unfortunately it will not trivial for me to reproduce it again.

Hello everyone,

I'm getting this error twice/day, so fortunately I'm able to
reproduce it.

IIRC, there was a patch for this, but it got lost...

I will take a look anyway.

ok, thanks for the response. Let me know when there will be a patch
available to test.

It has been reported here:
https://bugzilla.kernel.org/show_bug.cgi?id=109581

And there is a workaround from Konstantin:
https://patchwork.ozlabs.org/patch/803885/

Unfortunately I don't think that is a real fix, we probably need to
fix HFSC itself rather than just workaround the qlen==0. It is not
trivial since HFSC implementation is not easy to understand.
Maybe Jamal knows better than me.

Sorry for the latency - I looked at this on the plane and it is very
specific to fq/codel. It is not clear to me why codel needs this but
i note it has been there from the initial commit and from that
perspective the patch looks reasonable. In any case:
Punting it to Eric (on Cc).

cheers,
jamal

Thanks