Re: [PATCH v8 09/15] mm: Remove locking mf_mutex in is_raw_hwpoison_page_in_hugepage()

On Fri, Jul 31, 2026 at 09:07:54PM +0100, Matthew Wilcox (Oracle) wrote:
> Sleeping in this kind of predicate is unexpected.  Add a new spinlock
> to protect access to the list, and turn it into a normal singly linked
> list now that it doesn't need to be a lockless list.
> 

Out of curiosity, wouldn't sleeping in this context not just be
unexpected but theoretically cause issues? (mid-poison, sleep, scheduled
process generates more poison on the same page...) - at a minimum this
takes a thread out of the future potential poison-generating pool?

I don't see any particular issue with the patch, just curious the
implication of removable sleepability from this context.

> Rename is_raw_hwpoison_page_in_hugepage() to hugetlb_page_hwpoison()
> and make it take the folio (since the callers naturally have the folio).
> Also remove the handling of non-hugetlb folios and make the arguments
> const.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>

Reviewed-by: Gregory Price (Meta) <[email protected]>