Re: [PATCH v4 07/14] clocksource: mips-gic-timer: Always use cluster 0 counter as clocksource

[Jiaxun Yang]

在2024年7月9日七月 上午12:36，Daniel Lezcano写道：
> On 11/05/2024 12:43, Aleksandar Rikalo wrote:
>> From: Paul Burton <paulburton@xxxxxxxxxx>
>> 
>> In a multi-cluster MIPS system we have multiple GICs - one in each
>> cluster - each of which has its own independent counter. The counters in
>> each GIC are not synchronised in any way, so they can drift relative to
>> one another through the lifetime of the system. This is problematic for
>> a clocksource which ought to be global.
>> 
>> Avoid problems by always accessing cluster 0's counter, using
>> cross-cluster register access. This adds overhead so we only do so on
>> systems where we actually have CPUs present in multiple clusters.
>> For now, be extra conservative and don't use gic counter for vdso or
>> sched_clock in this case.
>> 
>> Signed-off-by: Paul Burton <paulburton@xxxxxxxxxx>
>> Signed-off-by: Chao-ying Fu <cfu@xxxxxxxxxxxx>
>> Signed-off-by: Dragan Mladjenovic <dragan.mladjenovic@xxxxxxxxxx>
>> Signed-off-by: Aleksandar Rikalo <aleksandar.rikalo@xxxxxxxxxx>
>> ---
>
> Applied patch 7 and 8

I think it won't compile without patch 1 being applid.

Thomas, do you mind to apply patch 1 for now? Given that it's just some extra
function definitions.

Thanks
- Jiaxun

>
> Thanks
>
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- Jiaxun