Re: [PATCH v3 1/4] hugetlb: Fix wrong use of nr_online_nodes

[Mike Kravetz]

On 4/12/22 20:29, Peng Liu wrote:
> Certain systems are designed to have sparse/discontiguous nodes. In
> this case, nr_online_nodes can not be used to walk through numa node.
> Also, a valid node may be greater than nr_online_nodes.
> 
> However, in hugetlb, it is assumed that nodes are contiguous. Recheck
> all the places that use nr_online_nodes, and repair them one by one.
> 
> Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
> Fixes: 4178158ef8ca ("hugetlbfs: fix issue of preallocation of gigantic pages can't work")
> Fixes: b5389086ad7b ("hugetlbfs: extend the definition of hugepages parameter to support node allocation")
> Fixes: e79ce9832316 ("hugetlbfs: fix a truncation issue in hugepages parameter")
> Fixes: f9317f77a6e0 ("hugetlb: clean up potential spectre issue warnings")
> Signed-off-by: Peng Liu <liupeng256@xxxxxxxxxx>
> ---
>  mm/hugetlb.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)

Thank you!

I am guessing that at one time nodes were contiguous at least at boot time.
When that changed, hugetlb was not updated. :(

Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
-- 
Mike Kravetz