Re: panics related to nfit_test?

[Linda Knippers <ljknh-DaQTI0RpDDMAvxtiuMwx3w@public.gmane.org>]

On 04/07/2017 05:46 PM, Dan Williams wrote:
> On Fri, Apr 7, 2017 at 1:28 PM, Linda Knippers <linda.knippers-ZPxbGqLxI0U@public.gmane.org> wrote:
>> On 04/07/2017 01:12 PM, Linda Knippers wrote:
>>> On 04/07/2017 12:44 PM, Dan Williams wrote:
>>>> On Fri, Apr 7, 2017 at 6:28 AM, Linda Knippers <linda.knippers-ZPxbGqLxI0U@public.gmane.org> wrote:
>>>> I've seen reports of this crash
>>>> signature from the team trying to integrate the ndctl unit tests into
>>>> the 0day kbuild robot, but I have thus far been unable to reproduce
>>>> them. On my system if I do:
>>>>
>>>> # modprobe nfit_test
>>>> # rmmod nfit_test
>>>> rmmod: ERROR: Module nfit_test is in use
>>>>
>>>> Are you saying you are able to remove nfit_test on your system without
>>>> first disabling regions?
>>>
>>> No, sorry.  I missed that step in my description.  I'm doing 'ndctl disable-region all'
>>> before the rmmod.
>>
>> I've been doing a bit more testing and once, I had 'ndctl check' make it through
>> all the tests and pass.  A few times I've made it part way through the tests before
>> I hit the panic.  However, if I just modprobe the modules, disable the regions,
>> and then rmmod nfit_test, it panics for me 100% of the time.  Try this in a script.
>>
>> modprobe nfit
>> modprobe dax
>> modprobe dax_pmem
>> modprobe libnvdimm
>> modprobe nd_blk
>> modprobe nd_btt
>> modprobe nd_e820
>> modprobe nd_pmem
>> lsmod |grep nfit
>> modprobe nfit_test
>> lsmod |grep nfit
>> ndctl disable-region all
>> rmmod nfit_test
>>
> 
> What distribution are you using? This loop is running fine in my
> Fedora Rawhide virtual machine environment. The other report of this
> was from a Debian environment. So I wonder if there is some timing
> differences related to udev or libkmod that prevent me from hitting
> the failure condition?

I'm running RHEL7.3 with a 4.11-rc5 kernel on bare metal with no
physical NVDIMMs.   My system is a 2-socket box with E5-2695 v4
processors and a total of 72 cores with HT on.  Maybe you need
more cores.

-- ljk