[RFC PATCH 3/3] objtool/mcount: Add powerpc specific functions

[Christophe Leroy]

Le 21/03/2022 à 09:30, Christophe Leroy a écrit :
> 
> 
> Le 21/03/2022 à 08:56, Christophe Leroy a écrit :
>>
>>
>> Le 21/03/2022 à 03:27, Michael Ellerman a écrit :
>>> Christophe Leroy <christophe.leroy at csgroup.eu> writes:
>>>> Le 18/03/2022 à 13:26, Peter Zijlstra a écrit :
>>>>> On Fri, Mar 18, 2022 at 04:21:40PM +0530, Sathvika Vasireddy wrote:
>>>>>> This patch adds powerpc specific functions required for
>>>>>> 'objtool mcount' to work, and enables mcount for ppc.
>>>>>
>>>>> I would love to see more objtool enablement for Power :-)
>>>>
>>>> I have not received this series and I can't see it on powerpc patchwork
>>>> either (https://patchwork.ozlabs.org/project/linuxppc-dev/list/)
>>>>
>>>> Did you send it to linuxppc-dev list ? If not can you resend it there ?
>>>
>>> It is there, might have been delayed?
>>>
>>> http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=291129
>>>
>>> There are some CI failures.
>>>
>>
>> On PPC32 I get :
>>
>> [    0.000000] ftrace: No functions to be traced?
>>
>> Without this series I get:
>>
>> [    0.000000] ftrace: allocating 22508 entries in 17 pages
>> [    0.000000] ftrace: allocated 17 pages with 2 groups
>>
>>
> 
> 
> ppc64_defconfig on QEMU:
> 
> [    0.000000][    T0] ftrace: No functions to be traced?
> 
> Without your series:
> 
> [    0.000000][    T0] ftrace: allocating 38750 entries in 15 pages
> [    0.000000][    T0] ftrace: allocated 15 pages with 4 groups
> [    0.000000][    T0] trace event string verifier disabled
> 

ppc64le_defconfig on QEMU:

[    0.000000][    T0] ftrace: allocating 37236 entries in 14 pages
[    0.000000][    T0] ftrace: allocated 14 pages with 3 groups

Without your series:

[    0.000000][    T0] ftrace: allocating 37236 entries in 14 pages
[    0.000000][    T0] ftrace: allocated 14 pages with 3 groups

So it seems it works only on Little Endian.
Works neither on PPC32 nor on PPC64 Big Endian

Christophe