build failure of next-20220817 for amdgpu due to 7bc913085765 ("drm/amdkfd: Try to schedule bottom half on same core")

[Sudip Mukherjee]

On Thu, Aug 18, 2022 at 4:10 PM Randy Dunlap <rdunlap at infradead.org> wrote:
>
>
>
> On 8/18/22 03:43, Sudip Mukherjee wrote:
> > On Thu, Aug 18, 2022 at 3:09 AM Randy Dunlap <rdunlap at infradead.org> wrote:
> >>
> >>
> >>
> >> On 8/17/22 19:01, Alex Deucher wrote:
> >>> On Wed, Aug 17, 2022 at 6:03 PM Sudip Mukherjee (Codethink)
> >>> <sudipm.mukherjee at gmail.com> wrote:
> >>>>
> >>>> Hi All,
> >>>>
> >>>> Not sure if it has been reported, build of next-20220817 fails with the
> >>>> error:
> >>>>
> >>>> ERROR: modpost: "cpu_smallcore_map" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!
> >>>>
> >>>> Trying to do a git bisect to find out the offending commit.
> >>>>
> >>>
> >>> Thanks.  I don't see that symbol in the driver at all.  Not sure where
> >>> it is coming from.
> >>>
> >>
> >> It's powerpc only.
> >>
> >> Sudip, is it non-CONFIG_SMP by any chance?
> >
> > Ohhh.. really sorry for the incomplete report. I should not try to
> > mail while travelling.
> >
> > The error is seen with powerpc allmodconfig and it has CONFIG_SMP=y.
>
> OK, I see that also, but it doesn't make any sense (to me).
>
> I did 'objdump' on the code file (amdgpu.o) and it's listed as
> undefined but there are no code references to it.

cpu_smt_mask() is called by drivers/gpu/drm/amd/amdkfd/kfd_device.c.
and cpu_smt_mask() is an inline function in
arch/powerpc/include/asm/smp.h which is doing "return
per_cpu(cpu_smallcore_map, cpu);"

So, the offending commit is 7bc913085765 ("drm/amdkfd: Try to schedule
bottom half on same core").


-- 
Regards
Sudip