Re: [PATCH V2] mm/hugetlb: add is_resv_equal_free() func

[Andrew Morton]

On Fri, 16 Sep 2022 14:41:27 +0800 Xin Hao <xhao@xxxxxxxxxxxxxxxxx> wrote:

> In hugetlb.c file, there are several places to compare the values of
> 'h->free_huge_pages' and 'h->resv_huge_pages', it looks a bit messy, so
> there add a new is_resv_equal_free() func to do these.
> 
> ...
>
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1191,6 +1191,11 @@ static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask,
>  	return NULL;
>  }
> 
> +static inline bool is_resv_equal_free(struct hstate *h)

I'm not sure that's a well chosen name.  A better name would reflect
the *meaning* of free_huge_pages being equal to resv_huge_pages.  Maybe
something like reserves_exhausted()?

This would all be clearer if we'd bothered to document the fields of
struct hstate :(


> +{
> +	return (h->free_huge_pages - h->resv_huge_pages == 0) ? true : false;

	return h->free_huge_pages == h->resv_huge_pages;

> +}