Re: ANON_LARGE_FOLIOS meeting follow-up & refined proposal

[David Hildenbrand <david@redhat.com>]

[sorry, busy with 100 different things]

> 
> DavidR suggested adding ability to set a VMA-specific LAF order, using
> process_madvise():
>      - Optionally accept LAF order through flags param of
>        process_madvise(MADV_LARGEFOLIO)
>      - When no LAF order passed, (or called with madvise()) use global LAF order
> 
> Personally, I would prefer to avoid vma-specific laf order for an initial
> submission and instead defer the addition until clear need is identified.
> Thoughts?

Yes, let's start with the simple cases.

> 
> 
> Stats
> -----
> 
> meminfo:AnonHugePages, smaps:AnonHugePages and memory.stat:anon_thp will
> continue to account THP only.

Agreed. One concern that was brought up that existing users associate 
"huge" with "pmd-size". So any thp toggles/stats should control/express 
exactly that for now.

> 
> I plan to add meminfo:AnonLargeFolio, smaps:AnonLargeFolio and
> memory.stat:anon_large_folio to account LAFs.
> 
> Do I need to add counters to vmstat also? (e.g. large_folio_fault_alloc,
> large_folio_fault_fallback, etc) - would need to think about which counters and
> what they mean if so.

Can probably be added later.

-- 
Cheers,

David / dhildenb