Re: [PATCH v2 00/12] fuse: support large folios

Shakeel Butt
2024-12-09T17:23:52Z

On Fri, Dec 06, 2024 at 10:33:56PM +0000, Matthew Wilcox wrote:
> On Fri, Dec 06, 2024 at 02:27:36PM -0800, Shakeel Butt wrote:
> > For anon memory or specifically THPs allocation, we can tune though
> > sysctls to be less aggressive but there is infrastructure like
> > khugepaged which in background converts small pages into THPs. I can
> > imagine that we might want something similar for filesystem as well.
>
> khugepaged also works on files. Where Somebody Needs To Do Something
> is that right now it gives up if it sees large folios (because it was
> written when there were two sizes of folio -- order 0 and PMD_ORDER).
> Nobody has yet taken on making it turn order-N folios into PMD_ORDER
> folios. Perhaps you'd like to do that?

I was hoping the mTHP work for khugepaged (haven't checked the latest
their yet) would add the necessary building block and adding file
support would be trivial. I will check the latest there and see what we
can do there sometime next year.