Re: [PATCH 4/4] hugetlb: Remove redundant VM_BUG_ON() in add_reservation_in_range()

From: Mike Kravetz
Date: Fri Oct 22 2021 - 19:57:35 EST


On 10/20/21 11:31 PM, Baolin Wang wrote:
> When calling hugetlb_resv_map_add(), we've guaranteed that the parameter
> 'to' is always larger than 'from', so it never returns a negative value
> from hugetlb_resv_map_add(). Thus remove the redundant VM_BUG_ON().
>
> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
> ---
> mm/hugetlb.c | 1 -
> 1 file changed, 1 deletion(-)

Thanks! You are correct, we could never trigger that VM_BUG_ON.

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

--
Mike Kravetz

>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 5922629..166cfa1 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -446,7 +446,6 @@ static long add_reservation_in_range(struct resv_map *resv, long f, long t,
> add += hugetlb_resv_map_add(resv, rg, last_accounted_offset,
> t, h, h_cg, regions_needed);
>
> - VM_BUG_ON(add < 0);
> return add;
> }
>
>