[OE-core] [PATCH] kernel.bbclass: Fix do_shared_workdir task ordering

[Bruce Ashfield]

On Tue, Aug 11, 2015 at 8:47 AM, Otavio Salvador
<otavio.salvador at ossystems.com.br> wrote:
> On Tue, Aug 11, 2015 at 12:23 AM, Bruce Ashfield
> <bruce.ashfield at gmail.com> wrote:
>> On Mon, Aug 10, 2015 at 11:21 AM, Stefan Müller-Klieser
>> <s.mueller-klieser at phytec.de> wrote:
>>> commit 02d0a003d60326 [kernel.bbclass: Fix race condition] has surfaced
>>> a bug in the generation of the shared_workdir. The task
>>> do_compile_kernelmodules adds the exported symbols of the kernel modules
>>> to the Module.symvers. By creating the shared_workdir before the modules
>>> are compiled, the symbols of the modules are missing in the
>>> shared_workdir. Subsequent external module builds will not include the
>>> ABI CRC of functions exported in modules. Modprobe will fail to load the
>>> external module if CONFIG_MODVERSIONS is enabled.\
>>
>> Have you seen our bug: https://bugzilla.yoctoproject.org/show_bug.cgi?id=8127 ?
>>
>> It's new .. so probably not.
>>
>> The significant issue with this, is that we are now forcing anyone
>> that needs the
>> shared workdir artifacts to build kernel modules.
>>
>> That's performance issue for many workflows.
>>
>> I had some changes where I was working to short cut parts of the process, but
>> they turned out to miss a few corner cases.
>>
>> We need to do more thinking on this one, before we can bring in a change like
>> this .. since avoiding that overhead is something valuable.
>
> I agree that performance is important but correctness seems more
> valuable for me. I think the optimization can come as a subsequent
> patch ...

Let's disagree on this point.

There's time to get this right. We have a bug to track it, so we wont'
release with
the active bug, and this only hits a very tiny set of users.

So we are going to step back and try and fix this right.

Bruce

>
> --
> Otavio Salvador                             O.S. Systems
> http://www.ossystems.com.br        http://code.ossystems.com.br
> Mobile: +55 (53) 9981-7854            Mobile: +1 (347) 903-9750



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