ppc64le vmlinuz is huge when building with BTF

[Naveen N Rao]

[Cc linuxppc-dev]

Dominique Martinet wrote:
> 
> Alan Maguire wrote on Thu, Jun 15, 2023 at 03:31:49PM +0100:
>> However the problem I suspect is this:
>> 
>>  51 .debug_info   0a488b55  0000000000000000  0000000000000000  026f8d20
>>  2**0
>>                   CONTENTS, READONLY, DEBUGGING
>> [...]
>> 
>> The debug info hasn't been stripped, so I suspect the packaging spec
>> file or equivalent - in perhaps trying to preserve the .BTF section -
>> is preserving debug info too. DWARF needs to be there at BTF
>> generation time in vmlinux but is usually stripped for non-debug
>> packages.
> 
> Thanks Alan and Eduard!
> I guess I should have checked that first, it helps.
> 
> We're not stripping anything in vmlinuz for other archs -- the linker
> script already should be including only the bare minimum to decompress
> itself (+compressed useful bits), so I guess it's a Kbuild issue for the
> arch.

For a related discussion, see:
http://lore.kernel.org/CAK18DXZKs2PNmLndeGYqkPxmrrBR=6ca3bhyYCj=GhyA7dHfAQ@mail.gmail.com

> We can add a strip but I unfortunately have no way of testing ppc build,
> I'll ask around the build linux-kbuild and linuxppc-dev lists if that's
> expected; it shouldn't be that bad now that's figured out.

Stripping vmlinux would indeed be the way to go. As mentioned in the 
above link, fedora also packages a strip'ed vmlinux for ppc64le:
https://src.fedoraproject.org/rpms/kernel/blob/4af17bffde7a1eca9ab164e5de0e391c277998a4/f/kernel.spec#_1797


- Naveen