Re: [PATCH v13 4/7] arm64: mte: Enable TCO in functions that can read beyond buffer limits

[Vincenzo Frascino]

On 2/23/21 12:05 PM, Catalin Marinas wrote:
>> I totally agree on this point. In the case of runtime switching we might need
>> the rethink completely the strategy and depends a lot on what we want to allow
>> and what not. For the kernel I imagine we will need to expose something in sysfs
>> that affects all the cores and then maybe stop_machine() to propagate it to all
>> the cores. Do you think having some of the cores running in sync mode and some
>> in async is a viable solution?
> stop_machine() is an option indeed. I think it's still possible to run
> some cores in async while others in sync but the static key here would
> only be toggled when no async CPUs are left.
> 

In such a case we might need to track the state based on cpuid() and have a mask
that tells us when cpus are all sync.
Not as expensive as stop_machine() but still requires a valid use case to be
introduced according to me.

-- 
Regards,
Vincenzo