On 09.07.24 04:17, Jason A. Donenfeld wrote:

Hi David,

On Mon, Jul 08, 2024 at 10:21:09PM +0200, David Hildenbrand wrote:

quoted

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.

Okay, just to be clear: no swap/zram/zswap. The reclaim code regarding 
not scanning anonymous memory without swap was a bit confusing.

thanks!

-- 
Cheers,

David / dhildenb