Re: [PATCH v4 0/2] mm: add per-order mTHP alloc and swpout counters

[Barry Song]

On Sat, Apr 6, 2024 at 9:11 AM Andrew Morton <akpm@linux-foundationorg> wrote:
>
> On Fri,  5 Apr 2024 23:27:02 +1300 Barry Song <21cnbao@xxxxxxxxx> wrote:
>
> > The patchset introduces a framework to facilitate mTHP counters, starting
> > with the allocation and swap-out counters. Currently, only four new nodes
> > are appended to the stats directory for each mTHP size.
> >
> > /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats
> >       anon_alloc
> >       anon_alloc_fallback
> >       anon_swpout
> >       anon_swpout_fallback
>
> Please let's get these documented?

Sure, I will do it.

Furthermore, after careful consideration, I suggest renaming anon_alloc to
anon_fault_alloc and anon_alloc_fallback to anon_fault_fallback. This
renaming is consistent with the naming convention observed in
thp_fault_alloc and thp_fault_fallback in vmstat. Additionally, this
modification will facilitate the handling of large folio swap-ins.

/sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats
           anon_fault_alloc,
           anon_fault_fallback,
           anon_swpin_alloc,
           anon_swpin_fallback,

Otherwise, without this renaming, it would be difficult to
differentiate fault_alloc
from swpin_alloc.

Hi David, Ryan,
I would also appreciate your input on the modification I am considering.

> Documentation/admin-guide/mm/transhuge.rst seems to be the place, and
> under Documentation/ABI.

Thanks
Barry