Re: [PATCH v21 1/4] mm: add VM_DROPPABLE for designating always lazily freeable mappings

[Jason A. Donenfeld]

Hi David,

On Mon, Jul 08, 2024 at 10:21:09PM +0200, David Hildenbrand wrote:
> BTW, I was just trying to understand how MADV_FREE + MAP_DROPPABLE would 
> behave without any swap space around.
> 
> Did you experiment with that?

You mean on a system without any swap configured? That's actually my
primary test environment for this. It behaves as expected: when ram
fills up and the scanner is trying to reclaim what it can,
folio_test_swapbacked(folio) is false, and the memory gets freed. After,
reads fault in a zero page. So it's working as expected.

Jason