Re: [PATCH v8 4/7] x86/mm: Simplify clear_page_*

Ankur Arora
2025-10-29T23:27:28Z

Borislav Petkov <bp@alien8.de> writes:

> On Mon, Oct 27, 2025 at 01:21:06PM -0700, Ankur Arora wrote:
>> +/**
>> + * clear_page() - clear a page using a kernel virtual address.
>> + * @addr: address of kernel page
>> + *
>> + * Switch between three implementations of page clearing based on CPU
>> + * capabilities:
>> + *
>> + * - memzero_page_aligned_unrolled(): the oldest, slowest and universally
>
> So I don't see how a memzero_<bla> name shows that it belongs to the
> clear_page "stack" of functions? clear_page_orig() kinda conveys better what
> this thing is. In any case, having "clear_page" somewhere there in the name
> should stay.

After this change the only remaining functions in x86/lib/clear_page_64.S are
this one and rep_stos_alternative.

And so the _orig suffix seemed to be a little confusing. That's why the
change to the more functional name.

>> + * supported method. Zeroes via 8-byte MOV instructions unrolled 8x
>> + * to write a 64-byte cacheline in each loop iteration..
> ^
>
> one fullstop is enough.
>
>> + *
>> + * - "rep stosq": really old CPUs had crummy REP implementations.
>
> We spell all x86 insns in ALL CAPS. Like you've almost done.
>
> Also, it is
>
> REP; STOSQ
>
> with a ;
>
> Otherwise the idea for the cleanup makes sense.

Thanks. Will fix the above.

--
ankur