Hi,

On Tue, May 12, 2026 at 9:46 AM Fujunjie [off-list ref] wrote:

quoted

On 5/12/2026 12:20 PM, Alexandre Ghiti wrote:

quoted

So I have been working on the exact same thing for some weeks now. My work is based on Usama's series [1].

The problem with large folio swapin is that it can create swap thrashing: to swap in a large folio, swap out may be necessary, as reported in [2].

I implemented quite a few throttling algorithms on top to try to avoid this issue and so far, I have had mixed/inconsistent results.

How did you test this series? Did you encounter thrashing? Do you have performance numbers?

Happy to talk more about this, thanks for your series!

Alex

[1] https://lore.kernel.org/all/20241018105026.2521366-1-usamaarif642@gmail.com/ (local)  <https://lore.kernel.org/all/20241018105026.2521366-1-usamaarif642@gmail.com/ (local) >
[2] https://lore.kernel.org/all/SJ0PR11MB5678A864244B09FDE4D914EEC9402@SJ0PR11MB5678.namprd11.prod.outlook.com/ (local)  <https://lore.kernel.org/all/SJ0PR11MB5678A864244B09FDE4D914EEC9402@SJ0PR11MB5678.namprd11.prod.outlook.com/ (local) >

Thanks Alexandre.

My RFC only had correctness testing so far. I tested the all-zswap path
and fallback cases under QEMU, but I don't have bare-metal
performance numbers yet.

If you are already actively working on this, I don't want to duplicate the
same effort. I will pause this RFC for now and wait for your series.

After your series is posted, I will take another look and see if there is
anything that still needs follow-up work.

Thanks for letting me know.

Sorry for the late answer. I took a break because of the inconsistent
results that I had, perhaps a fresh look could help so no worries if
you give it a try on your end.

Happy to discuss further results if you continue.

Alex