On Tue, Jul 07, 2020 at 04:02:04PM +1200, Barry Song wrote:
> hugetlb_cma[0] can be NULL due to various reasons, for example, node0 has
> no memory. so NULL hugetlb_cma[0] doesn't necessarily mean cma is not
> enabled. gigantic pages might have been reserved on other nodes.
>
> Fixes: cf11e85fc08c ("mm: hugetlb: optionally allocate gigantic hugepages using cma")
> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
> Cc: Jonathan Cameron <jonathan.cameron@xxxxxxxxxx>
> Acked-by: Roman Gushchin <guro@xxxxxx>
> Signed-off-by: Barry Song <song.bao.hua@xxxxxxxxxxxxx>
Acked-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> ---
> -v3: add acked-by; make code more canonical
>
> mm/hugetlb.c | 16 +++++++++++++++-
> 1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 57ece74e3aae..d293c823121e 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -2546,6 +2546,20 @@ static void __init gather_bootmem_prealloc(void)
> }
> }
>
> +bool __init hugetlb_cma_enabled(void)
> +{
> +#ifdef CONFIG_CMA
> + int node;
> +
> + for_each_online_node(node) {
> + if (hugetlb_cma[node])
> + return true;
> + }
> +#endif
> +
> + return false;
> +}
> +
> static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
> {
> unsigned long i;
> @@ -2571,7 +2585,7 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
>
> for (i = 0; i < h->max_huge_pages; ++i) {
> if (hstate_is_gigantic(h)) {
> - if (IS_ENABLED(CONFIG_CMA) && hugetlb_cma[0]) {
> + if (hugetlb_cma_enabled()) {
> pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n");
> break;
> }
> --
> 2.27.0
>
>
>
--
Sincerely yours,
Mike.
