next/master boot: 273 boots: 63 failed, 209 passed with 1 untried/unknown (next-20171106)

[Jon Hunter]

On 09/11/17 13:17, Arnd Bergmann wrote:
> On Thu, Nov 9, 2017 at 1:51 PM, Guillaume Tucker
> <guillaume.tucker at collabora.com> wrote:
>> On 09/11/17 11:29, Jon Hunter wrote:
>>>
>>>
>>> On 09/11/17 10:43, Guillaume Tucker wrote:
>>>
>>> ...
>>>
>>>> I actually built these kernel revisions with module support
>>>> disabled to speed up the builds, and no modules are being
>>>> downloaded in the LAVA job.
>>>>
>>>> If you have a public URL with your known working kernel zImage
>>>> and dtb, let me know so I could re-run the same test LAVA boot
>>>> test to see if I get the same results as you (i.e. no hang).
>>>
>>>
>>> I don't have a public URL for the zImage but I can definitely email it
>>> to you. By the way, when booting I am setting 'init=/bin/bash' so no
>>> start-up scripts are running.
>>
>>
>> Thanks, I tried your binary and it booted fine.  I built
>> next-20171109 again with and without loadable module support
>> enabled and it fails with it disabled but passes with it
>> enabled (even without actually loading any modules):
>>
>>   * with CONFIG_MODULES disabled (fails):
>>     https://lava.collabora.co.uk/scheduler/job/981215
>>
>>   * with plain multi_v7_defconfig and no modules loaded (passes):
>>     https://lava.collabora.co.uk/scheduler/job/981217
>>
>>
>> So I guess this means disabling loadable modules support has some
>> interesting side-effects that cause the kernel to crash.  I think
>> the kci builds all leave modules enabled with multi_v7_defconfig,
>> so the failing boots must be due to something else.  Taking
>> another look at the failing kci boots now...
> 
> The one thing that comes to mind that happened recently with
> modules is
> 
> 371435f78e9e ("kernel debug: support resetting WARN_ONCE for all architectures")
> 
> Can you try reverting this? It's probably something else, but I'd like
> to rule it out.

I have been able to reproduce the problem by disabling support for
loadable modules on both Tegra124 Nyan-Big and Jetson TK1. Disabling
DRM_NOUVEAU appears to avoid the problem.

Guillaume can you try the same?

Cheers
Jon

-- 
nvpublic