Re: [PATCH] mm: Add AnonZero accounting for zero-filled anonymous pages

[David Hildenbrand (Arm)]

On 2/16/26 12:34, Kiryl Shutsemau wrote:
> On Sat, Feb 14, 2026 at 04:45:14PM +0800, Wenchao Hao wrote:
> > Add kernel command line option "count_zero_page" to track anonymous pages
> > have been allocated and mapped to userspace but zero-filled.
> >
> > This feature is mainly used to debug large folio mechanism, which
> > pre-allocates and map more pages than actually needed, leading to memory
> > waste from unaccessed pages.
> >
> > Export the result in /proc/pid/smaps as "AnonZero" field.
>
> I expect it to slowdown /proc/pid/smaps read substantially. I don't
> think this line in smaps worth it.

That's why it's enabled through a command line parameter.

--
Cheers,

David