Re: [RFC PATCH 0/5] mm: support zswap-backed anonymous large folio swapin

[Fujunjie]

On 5/12/2026 12:20 PM, Alexandre Ghiti wrote:
> 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@xxxxxxxxx/ <https://lore.kernel.org/all/20241018105026.2521366-1-usamaarif642@xxxxxxxxx/>
> [2] https://lore.kernel.org/all/SJ0PR11MB5678A864244B09FDE4D914EEC9402@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ <https://lore.kernel.org/all/SJ0PR11MB5678A864244B09FDE4D914EEC9402@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/>

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.