Re: [PATCH 5.8 000/186] 5.8.8-rc1 review

From: Guenter Roeck
Date: Wed Sep 09 2020 - 14:22:36 EST

On 9/9/20 11:01 AM, Greg Kroah-Hartman wrote:
> On Wed, Sep 09, 2020 at 09:47:05AM -0700, Guenter Roeck wrote:
>> On Tue, Sep 08, 2020 at 05:22:22PM +0200, Greg Kroah-Hartman wrote:
>>> This is the start of the stable review cycle for the 5.8.8 release.
>>> There are 186 patches in this series, all will be posted as a response
>>> to this one. If anyone has any issues with these being applied, please
>>> let me know.
>>> Responses should be made by Thu, 10 Sep 2020 15:21:57 +0000.
>>> Anything received after that time might be too late.
>> Build results:
>> total: 154 pass: 153 fail: 1
>> Failed builds:
>> powerpc:allmodconfig
>> Qemu test results:
>> total: 430 pass: 430 fail: 0
>> The powerpc problem is the same as before:
>> Inconsistent kallsyms data
>> Try make KALLSYMS_EXTRA_PASS=1 as a workaround
>> KALLSYMS_EXTRA_PASS=1 doesn't help. The problem is sporadic, elusive, and all
>> but impossible to bisect. The same build passes on another system, for example,
>> with a different load pattern. It may pass with -j30 and fail with -j40.
>> The problem started at some point after v5.8, and got worse over time; by now
>> it almost always happens. I'd be happy to debug if there is a means to do it,
>> but I don't have an idea where to even start. I'd disable KALLSYMS in my
>> test configurations, but the symbol is selected from various places and thus
>> difficult to disable. So unless I stop building ppc:allmodconfig entirely
>> we'll just have to live with the failure.
> Ah, I was worried when I saw your dashboard orange for this kernel.
> I guess the powerpc maintainers don't care? Sad :(

Not sure if the powerpc architecture is to blame. Bisect attempts end up
all over the place, and don't typically include any powerpc changes.
I have no idea how kallsyms is created, but my suspicion is that it is
a generic problem and that powerpc just happens to hit it right now.
I have added KALLSYMS_EXTRA_PASS=1 to several architecture builds over
time, when they reported similar problems. Right now I set it for
alpha, arm, and m68k. powerpc just happens to be the first architecture
where it doesn't help.