On Tue, Sep 01, 2020 at 10:49:24PM +0800, Li Xinhai wrote:
> Since commit cf11e85fc08cc6a4 ("mm: hugetlb: optionally allocate gigantic
> hugepages using cma"), the gigantic page would be allocated from node
> which is not the preferred node, although there are pages available from
> that node. The reason is that the nid parameter has been ignored in
> alloc_gigantic_page().
>
> Besides, the __GFP_THISNODE also need be checked if user required to
> alloc only from the preferred node.
>
> After this patch, the preferred node is tried first before other allowed
> nodes, and don't try to allocate from other nodes if __GFP_THISNODE is
> specified.
>
> Fixes: cf11e85fc08cc6a4 ("mm: hugetlb: optionally allocate gigantic hugepages using cma")
> Cc: Roman Gushchin <guro@xxxxxx>
> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxxxx>
> Signed-off-by: Li Xinhai <lixinhai.lxh@xxxxxxxxx>
> ---
> v1->v2:
> With review by Mike and Michal, need to check __GFP_THISNODE to avoid
> allocate from other nodes.
Acked-by: Roman Gushchin <guro@xxxxxx>
Thank you!
>
> mm/hugetlb.c | 21 +++++++++++++++------
> 1 file changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index a301c2d672bf..d24986145087 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1256,15 +1256,24 @@ static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask,
> struct page *page;
> int node;
>
> - for_each_node_mask(node, *nodemask) {
> - if (!hugetlb_cma[node])
> - continue;
> -
> - page = cma_alloc(hugetlb_cma[node], nr_pages,
> - huge_page_order(h), true);
> + if (nid != NUMA_NO_NODE && hugetlb_cma[nid]) {
> + page = cma_alloc(hugetlb_cma[nid], nr_pages,
> + huge_page_order(h), true);
> if (page)
> return page;
> }
> +
> + if (!(gfp_mask & __GFP_THISNODE)) {
> + for_each_node_mask(node, *nodemask) {
> + if (node == nid || !hugetlb_cma[node])
> + continue;
> +
> + page = cma_alloc(hugetlb_cma[node], nr_pages,
> + huge_page_order(h), true);
> + if (page)
> + return page;
> + }
> + }
> }
> #endif
>
> --
> 2.18.4
>
