Revert "mm/dynamic_hugetlb: disable dynamic hugetlb if hugetlb_vmemmap is enabled"

hulk inclusion
category: bugfix
bugzilla: 187198, https://gitee.com/openeuler/kernel/issues/I5GVFO
CVE: NA

--------------------------------

Will disable hugetlb_vmemmap when dynamic hugetlb is enabled in later patch.

This reverts commit c7ae7c0d.
Signed-off-by: NLiu Shixin <liushixin2@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

mm/dynamic_hugetlb.c

@@ -1133,17 +1133,6 @@ void __init dynamic_hugetlb_init(void)
 	if (!enable_dhugetlb)
 		return;
 
-	/*
-	 * The dynamic_hugetlb feature need to split and merge pages frequently.
-	 * hugetlb_vmemmap will affects the perforemance of page split and merge.
-	 * If want to use dynamic hugetlb, please disable hugetlb_vmemmap.
-	 */
-	if (hugetlb_free_vmemmap_enabled) {
-		enable_dhugetlb = false;
-		pr_info("Please set hugetlb_free_vmemmap=off if want to enable dynamic hugetlb\n");
-		return;
-	}
-
 	count = max(hugepage_index(max_pfn), (unsigned long)DEFAULT_PAGELIST_COUNT);
 	size = sizeof(struct dhugetlb_pagelist) + count * sizeof(struct dhugetlb_pool *);
 	dhugetlb_pagelist_t = kzalloc(size, GFP_KERNEL);