[linux-yocto] [PATCH 2/2] intel-x86-64: Move 'CONFIG_NR_CPUS=256' to intel-x86-64.cfg

[Bruce Ashfield]

On 2018-11-08 8:45 p.m., Hongzhi, Song wrote:
> 
> 
> On 11/09/2018 03:56 AM, Bruce Ashfield wrote:
>> On 2018-11-07 9:05 p.m., Hongzhi.Song wrote:
>>> The maximum cpus are 64 on intel-x86-32.
>>> But intel-x86-64 support ranges from 1 to 8192.
>>> So we should move the config to intel-x86-64.cfg.
>>
>> ok. This makes more sense, but two questions:
>>
>>  - why limit to 256 on x86-64 ?
> 
> Hi Bruce,
> 
> The config file which contains '256' was transplanted from the 
> historical branch.
> 
> I have consulted the committer, Yongxin Liu <yongxin.liu at windriver.com>, 
> who said:
> for most x86-64 products, 256 was an usual value.
> [add Yongxin in loop]
> 
> 
>>  - why not put 64 as the limit in intel-x86.cfg, since
>>    it now has no setting at all.
> 
> The default value is 64 on intel-x86-32.
> So I doesn't explicitly set the config to 64 in intel-x86.cfg, but
> set 256 explicitly in intel-x86-64.

I'd still rather have it explicitly set. We do sometimes rely
on defaults, but it is often better to have the fragments
be self-documenting and be independent of changing defaults
in the kernels.

> 
> By the way, intel-x86.cfg is shared by 32bit and 64bit.

Indeed. That would be a problem in setting the value to 64
explicitly in that fragment.

I'll merge this as-is, but I would rather have something that
explicitly sets the value for 32 bit .. something for a future
re-org of the fragments to take care of.

Bruce

> 
> --Hongzhi
> 
>>
>> Bruce
>>
>>>
>>> Signed-off-by: Hongzhi.Song <hongzhi.song at windriver.com>
>>> ---
>>>   bsp/intel-x86/intel-x86-64.cfg | 3 +++
>>>   bsp/intel-x86/intel-x86.cfg    | 1 -
>>>   2 files changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/bsp/intel-x86/intel-x86-64.cfg 
>>> b/bsp/intel-x86/intel-x86-64.cfg
>>> index 4e8a4d7..215c0f0 100644
>>> --- a/bsp/intel-x86/intel-x86-64.cfg
>>> +++ b/bsp/intel-x86/intel-x86-64.cfg
>>> @@ -49,3 +49,6 @@ CONFIG_CRYPTO_DEV_QAT_DH895xCCVF=m
>>>     # Intel Resource Director Technology support
>>>   CONFIG_INTEL_RDT=y
>>> +
>>> +# Processor type and features
>>> +CONFIG_NR_CPUS=256
>>> diff --git a/bsp/intel-x86/intel-x86.cfg b/bsp/intel-x86/intel-x86.cfg
>>> index 6919179..080bca1 100644
>>> --- a/bsp/intel-x86/intel-x86.cfg
>>> +++ b/bsp/intel-x86/intel-x86.cfg
>>> @@ -17,7 +17,6 @@
>>>   CONFIG_MCORE2=y
>>>   CONFIG_SMP=y
>>>   CONFIG_SCHED_SMT=y
>>> -CONFIG_NR_CPUS=256
>>>     CONFIG_NUMA=y
>>>   CONFIG_ACPI_NUMA=y
>>>
>>
>>
>