Re: [PATCH 2/2] mm: compaction: fix the possible deadlock when isolating hugetlb pages

[Baolin Wang]

On 3/15/2023 1:27 AM, Mike Kravetz wrote:
> On 03/14/23 12:11, Baolin Wang wrote:
> > On 3/14/2023 1:08 AM, Mike Kravetz wrote:
> > > On 03/13/23 18:37, Baolin Wang wrote:
> > >
> > > It would seem that the pfn of a hugetlb page would always be a multiple of
> > > COMPACT_CLUSTER_MAX so we would drop the lock.  However, I am not sure if
> > > that is ALWAYS true and would prefer something like the code you suggested.
> >
> > Well, this is not always true, suppose the CONT-PTE hugetlb on ARM arch,
> > which contains 16 contiguous normal pages.
>
> Right.  I keep forgetting about the CONT-* page sizes on arm :(
>
> In any case, I think explicitly dropping the lock as you have done is a
> good idea.
>
> Feel free to add,
>
> Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>

Thanks for reviewing.