Re: [RFC PATCH] mm/rmap: use release ordering for small-folio mapcount removal

[David Hildenbrand (Arm)]

On 11/4/26 10:46, Pranith Kumar wrote:
> Hi David,
> 
> Thank you for looking at the patch.
> 
> On Wed, Nov 4, 2026 at 1:16 AM David Hildenbrand (Arm) <david@xxxxxxxxxx> wrote:
>>
>>
>>> In an arm64 page map/unmap microbenchmark with 20,480 minor
>>> faults, simulated cycles fell by 1.54%.
>>
>> Thanks for the patch.
>>
>> While I see value, I am not convinced this is the right time for this
>> micro-optimization while we are busy with other things.
>>
>> This needs a better evaluation: 1.54% in a micro-benchmark without knowing the
>> stddev isn't particularly helpful.
>>
> 
> This result is from a deterministic simulation, hence no stddev.

Ah, I'd assume even a deterministic simulator would have some variance due to
preemption, TLB flushes etc.

But the bigger question is: which arm64 variant is simulated? I'd assume it
might vary heavily no?

-- 
Cheers,

David