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

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?