Re: [v2 00/16] mm: PMD-level swap entries for anonymous THPs

[Lance Yang]

On 2026/6/10 20:24, David Hildenbrand (Arm) wrote:
> On 6/9/26 16:29, Usama Arif wrote:
> > On 02/06/2026 15:24, Usama Arif wrote:
> > > When reclaim swaps out a PMD-mapped anonymous THP today, the PMD is
> > > split into 512 PTE-level swap entries via TTU_SPLIT_HUGE_PMD before
> > > unmap.
> > >
> > > This series introduces a PMD-level swap entry. The huge mapping is
> > > preserved across the swap round-trip, and do_huge_pmd_swap_page()
> > > resolves the entire 2 MB region in a single fault on swap-in,
> > > no khugepaged involvement is needed. swap_map metadata is identical
> > > either way (512 single-slot counts), so the PTE split buys nothing
> > > on the swap side, it is purely a page-table representation change.
> >
> > Hello!
> >
> > Just following up if there were any reviews/comments on this series!
> >
> > I know its a large series but was just checking if there was any
> > feedback?
>
> It shall be reviewed. We just finished the mTHP khugepaged review to get it into
> 7.2, so we've all been rather busy.

Right, mTHP khugepaged was a rough one. Glad we got it over the line,
but yeah, there's just been a lot of THP work lately. pretty nonstop ...

> (I mean, just take a look at the THP-related flood of patches we are fighting
> with on a daily basis, it's not funny anymore)
>
> This is clearly going to be 7.3 material, so there is plenty of time given that
> the merge window is about to open soon.

Usama, I'll try to make this one a priority too. Looks interesting :P

Cheers, Lance