Re: [PATCH v5 4/4] hugetlb: allow to free gigantic pages regardless of the configuration

[Dave Hansen]

On 3/6/19 11:00 AM, Alexandre Ghiti wrote:
> +static int set_max_huge_pages(struct hstate *h, unsigned long count,
> +			      nodemask_t *nodes_allowed)
>  {
>  	unsigned long min_count, ret;
>  
> -	if (hstate_is_gigantic(h) && !gigantic_page_supported())
> -		return h->max_huge_pages;
> +	/*
> +	 * Gigantic pages allocation depends on the capability for large page
> +	 * range allocation. If the system cannot provide alloc_contig_range,
> +	 * allow users to free gigantic pages.
> +	 */
> +	if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) {
> +		spin_lock(&hugetlb_lock);
> +		if (count > persistent_huge_pages(h)) {
> +			spin_unlock(&hugetlb_lock);
> +			return -EINVAL;
> +		}
> +		goto decrease_pool;
> +	}

We talked about it during the last round and I don't seen any mention of
it here in comments or the changelog: Why is this a goto?  Why don't we
just let the code fall through to the "decrease_pool" label?  Why is
this new block needed at all?  Can't we just remove the old check and
let it be?