Re: [PATCH 1/2] mm/compaction: skip folios containing hwpoisoned pages

[David Hildenbrand (Arm)]

On 10/26/26 03:57, Yuanhe Shu wrote:
> On 10/22/26 20:39, Kaitao Cheng wrote:
>> Here are a few subtle corner cases I came up with. They may be
>> extremely unlikely to occur.
> 
> Both cases set the flag while the memcpy still succeeds - that is
> the "how this makes sense" for checking after the copy: a check
> before it misses them, the recheck after it catches both, and the
> refusal is the same either way (the data is still good in case A,
> already bad in case B).  What no flag check, before or after, can
> catch is corruption whose hardware report lands after the last
> check; that needs architecture support, as David noted.

Yes. And you really want to avoid reading corrupt data an triggering some
undesired HW reaction (MCE )etc.

> 
> The migration paths spell out the same placement and races in v2
> (patch 2, just posted), and the fallback patch ("mm/highmem: refuse
> to copy hwpoisoned folios in the !copy_mc fallbacks") is posted as
> well, with the races in its changelog.

Sorry, which patches did you post? Do you have a link? Do the supersede
both patches here?
-- 
Cheers,

David