Re: [patch v2 -mm] mm, hugetlb: schedule when potentially allocating many hugepages

From: Mike Kravetz
Date: Fri Jun 09 2017 - 18:44:00 EST


On 06/09/2017 03:36 PM, David Rientjes wrote:
> A few hugetlb allocators loop while calling the page allocator and can
> potentially prevent rescheduling if the page allocator slowpath is not
> utilized.
>
> Conditionally schedule when large numbers of hugepages can be allocated.
>
> Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>

Thanks for doing this.

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

--
Mike Kravetz

> ---
> Based on -mm only to prevent merge conflicts with
> "mm/hugetlb.c: warn the user when issues arise on boot due to hugepages"
>
> v2: removed redundant cond_resched() per Mike
>
> mm/hugetlb.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1754,6 +1754,7 @@ static int gather_surplus_pages(struct hstate *h, int delta)
> break;
> }
> list_add(&page->lru, &surplus_list);
> + cond_resched();
> }
> allocated += i;
>
> @@ -2222,6 +2223,7 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
> } else if (!alloc_fresh_huge_page(h,
> &node_states[N_MEMORY]))
> break;
> + cond_resched();
> }
> if (i < h->max_huge_pages) {
> char buf[32];
>
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