Re: khugepaged / firefox going wild in 3.18-rc

Vlastimil Babka
2014-11-07T13:38:20Z

On 11/07/2014 02:07 PM, Norbert Preining wrote:
> Hi Vlastimil,
>
> On Thu, 06 Nov 2014, Vlastimil Babka wrote:
>> OK, one possibility is to do (it should apply cleanly)
>> git revert e14c720efdd73c6d69cd8d07fa894bcd11fe1973
>
> I am running with this reverted now, and I cannot reproduce the
> khugepage going overboard anymore.

Great, that's good news if I understand correctly, but ...

> I tried hard since 2 days now, no chance to reproduce.
> Before firefox or shotwell went into boom mode, but not now.
> (For now!)

I suggested the commit to you for revert 1 day ago, and you say you
can't reproduce it for 2 days already? That's a bit suspicious. Did you
already tried to revert it before my suggestion, or were you unable to
reproduce it anymore even before the revert?

>>> Again, as I mentioned, I don't have /proc/pid/stack for any "pid", is
>>> this depending on some specific kerenl option?
>>
>> Ah I missed that. Should be CONFIG_STACKTRACE to enable that.
>
> If you want, I can compile a "default" kernel without the above commit

Hmm it would probably be more useful if I sent you some debug printing
patches first... the stacktrace won't probably tell us much we don't
already know.

> reverted, and turn on STACKTRACE (I have turned it one for *all* future
> kernels I compile ;-)

Yeah that's a good idea :)

> I also didn't try the patch you send me, just the revert from above.

Yeah if the revert helped, the other patch probably wouldn't change
anything. It also didn't help the other guy with similar problem.

> Please let me know which other experiments you want to see.

I'll prepare a debugging patch and send with instructions. Meanwhile you
could send the /proc/zoneinfo contents? :)

Thanks!
Vlastimil

> Thanks
>
> Norbert
>
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> PREINING, Norbert http://www.preining.info
> JAIST, Japan TeX Live & Debian Developer
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