Re: [PATCH RFC 0/4] mm: Remember young bit for migration entries

[Peter Xu]

On Mon, Aug 01, 2022 at 01:33:28PM +0800, Huang, Ying wrote:
> If my understanding were correct, max_swapfile_size() provides a
> mechanism to identify the available bits with swp_entry_t and swap PTE
> considered.  We may take advantage of that?

That's an interesting trick, I'll have a closer look, thanks for the
pointer!

> 
> And according to commit 377eeaa8e11f ("x86/speculation/l1tf: Limit swap
> file size to MAX_PA/2"), the highest bit of swap offset needs to be 0 if
> L1TF mitigation is enabled.
> 
> Cced Andi for confirmation.

Yeah it'll be great to have a confirmation, hopefully max_swapfile_size()
should have covered that case.

-- 
Peter Xu