Re: next/master boot bisection: next-20190215 on beaglebone-black

[Vlastimil Babka]

On 2/27/19 1:04 AM, Dan Williams wrote:
> On Tue, Feb 26, 2019 at 4:00 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> On Fri, 15 Feb 2019 18:51:51 +0000 Mark Brown <broonie@xxxxxxxxxx> wrote:
>>
>>> On Fri, Feb 15, 2019 at 10:43:25AM -0800, Andrew Morton wrote:
>>>> On Fri, 15 Feb 2019 10:20:10 -0800 (PST) "kernelci.org bot" <bot@xxxxxxxxxxxx> wrote:
>>>
>>>>>   Details:    https://kernelci.org/boot/id/5c666ea959b514b017fe6017
>>>>>   Plain log:  https://storage.kernelci.org//next/master/next-20190215/arm/multi_v7_defconfig+CONFIG_SMP=n/gcc-7/lab-collabora/boot-am335x-boneblack.txt
>>>>>   HTML log:   https://storage.kernelci.org//next/master/next-20190215/arm/multi_v7_defconfig+CONFIG_SMP=n/gcc-7/lab-collabora/boot-am335x-boneblack.html
>>>
>>>> Thanks.
>>>
>>>> But what actually went wrong?  Kernel doesn't boot?
>>>
>>> The linked logs show the kernel dying early in boot before the console
>>> comes up so yeah.  There should be kernel output at the bottom of the
>>> logs.
>>
>> I assume Dan is distracted - I'll keep this patchset on hold until we
>> can get to the bottom of this.
> 
> Michal had asked if the free space accounting fix up addressed this
> boot regression? I was awaiting word on that.

I'm afraid it couldn't have. Bisection identified the "enable all
shuffling" patch, but the free area mis-accounting happened regardless
of shuffling being enabled. And if dropping the "enable all shuffling"
patch stopped the problem even before the misacounting fix was merged,
that's another confirmation.

Is it possible that the platform silently depends on large contiguous
areas without a proper CMA reservation, and the shuffling fragments
them? Or maybe the CMA reservation happens too late?

> I assume you're not willing to entertain a "depends
> NOT_THIS_ARM_BOARD" hack in the meantime?
>