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charset=us-ascii Content-Disposition: inline In-Reply-To: <3f9e8e12-2d51-4f2a-ada1-994ed24df284@linux.dev> On Wed, Apr 08, 2026 at 04:06:29PM +0100, Usama Arif wrote: > On 06/04/2026 00:34, Hugh Dickins wrote: > > What would help a lot would be the implementation of swap entries > > at the PMD level. Whether that would help enough, I'm sceptical: > > I do think it's foolish to depend upon the availability of huge > > contiguous swap extents, whatever the recent improvements there; > > but it would at least be an arguable justification. > > > Thanks for pointing this out. I should have thought of this as I > have been thinking about fork a lot for 1G THP and for this series. > > I am working on trying to make PMD level swap entires work. I hope > to have a RFC soon. I think you may have missed Hugh's point a little bit. If we do support PMD-level swap entries, that means we have to be able to find contiguous space in the swap space for 512 entries. I don't know how hard that will be, but I can imagine it's not that easy.