Re: [PATCH stable/linux-6.6.y] mm/memory-failure: fix missing ->mf_stats count when hugetlb folio already poisoned

[Qi Xi]

On 21/07/2026 21:06, Greg Kroah-Hartman wrote:
> On Tue, Jul 14, 2026 at 09:45:03AM +0800, Qi Xi wrote:
> > Add stable@ to Cc.
> >
> > On 06/07/2026 16:41, Qi Xi wrote:
> > > When a new subpage is poisoned on a hugetlb folio that has already been
> > > marked hwpoison (MF_HUGETLB_FOLIO_PRE_POISONED), hugetlb_update_hwpoison()
> > > increments num_poisoned_pages directly, but the per-node ->mf_stats is
> > > not updated because this path bypasses action_result(). This leaves the
> > > two accounting counters inconsistent within the hardware memory-failure
> > > path: a new poison event is counted in num_poisoned_pages but not reflected
> > > in the per-node mf_stats.
> > >
> > > In mainline, commit a148a2040191 ("mm/memory-failure: fix missing
> > > ->mf_stats count in hugetlb poison") fixed this by removing the direct
> > > num_poisoned_pages_inc() from the helper and adding action_result() calls
> > > in try_memory_failure_hugetlb() for the already-poisoned cases. The
> > > backport to linux-6.6.y as commit 252bb328b36f ("mm/memory-failure: fix
> > > missing ->mf_stats count in hugetlb poison") applied the refactoring
> > > (naming, constants, switch-case) but omitted the core counting fix,
> > > leaving the inconsistency in place.
> > >
> > > Fix this by adding a matching update_per_node_mf_stats() call alongside
> > > the existing num_poisoned_pages_inc() in the same block, so both counters
> > > stay consistent without restructuring the error path.
> > >
> > > Fixes: 252bb328b36f ("mm/memory-failure: fix missing ->mf_stats count in hugetlb poison")
> > > Signed-off-by: Qi Xi <xiqi2@xxxxxxxxxx>
> We need acks/reviews by the relevant maintainers before we can accept
> something like this.

Thank you for the feedback. I have resent this patch to
stable@xxxxxxxxxxxxxxx with the correct format (including upstream
commit reference and proper stable submission format):

https://lore.kernel.org/stable/20260721121956.124887-1-xiqi2@xxxxxxxxxx/

I'll also work on getting the required Reviewed-by/Acked-by from
the mm/memory-failure maintainers.

Qi

> thanks,
>
> greg k-h