Re: [PATCH] MIPS: CPS: Optimise delay CPU calibration for SMP

["Jiaxun Yang" <jiaxun.yang@flygoat.com>]

在2025年5月21日周三 上午8:47，Gregory CLEMENT写道：
> Hello Jiaxun,
>
>> 在2025年5月20日周二 下午4:21，Gregory CLEMENT写道：
>> [...]
>>>
>>> This allows to implement calibrate_delay_is_known(), which will return
>>> 0 (triggering calibration) only for the primary CPU of each
>>> cluster. For other CPUs, we can simply reuse the value from their
>>> cluster's primary CPU core.
>>
>> Is __cpu_primary_cluster_mask really necessary?
>>
>> Maybe we can just test if current CPU is the first powered up CPU
>> in the cluster?
>
> That is exactly the point of __cpu_primary_cluster_mask: setting in an
> efficient way the first powered-up CPU for each cluster. This adds only
> a single variable (which is actually just a long) and allows for minimal
> impact during boot time, by doing the minimum write and read operations
>
> I don't see a better alternative. What do you have in mind ?

Maybe we can try mips_cps_first_online_in_cluster()?

[...]

Thanks

-- 
- Jiaxun