Commit b4ecc9be authored by ZhangPeng's avatar ZhangPeng Committed by Jialin Zhang
Browse files

Revert "mm/vmalloc: huge vmalloc backing pages should be split rather than compound" 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6LD0S


CVE: NA

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

This reverts commit 49ed1f1e.

It will have a great impact on the product if we can't use vmalloc to
alloc high-order physical pages.

Signed-off-by: default avatarZhangPeng <zhangpeng362@huawei.com>
Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parent f25c3308

mm/vmalloc.c

+5 −17
Original line number Diff line number Diff line
@@ -2639,17 +2639,14 @@ static void __vunmap(const void *addr, int deallocate_pages) 
	vm_remove_mappings(area, deallocate_pages);



	if (deallocate_pages) {

		unsigned int page_order = vm_area_page_order(area);

		int i;



		for (i = 0; i < area->nr_pages; i++) {

		for (i = 0; i < area->nr_pages; i += 1U << page_order) {

			struct page *page = area->pages[i];



			BUG_ON(!page);

			/*

			 * High-order allocs for huge vmallocs are split, so

			 * can be freed as an array of order-0 allocations

			 */

			__free_pages(page, 0);

			__free_pages(page, page_order);

		}

		atomic_long_sub(area->nr_pages, &nr_vmalloc_pages);
@@ -2929,7 +2926,8 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, 
		struct page *page;

		int p;



		page = alloc_pages_node(node, gfp_mask, page_order);

		/* Compound pages required for remap_vmalloc_page */

		page = alloc_pages_node(node, gfp_mask | __GFP_COMP, page_order);

		if (unlikely(!page)) {

			/* Successfully allocated i pages, free them in __vfree() */

			area->nr_pages = i;
@@ -2941,16 +2939,6 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, 
			goto fail;

		}



		/*

		 * Higher order allocations must be able to be treated as

		 * indepdenent small pages by callers (as they can with

		 * small-page vmallocs). Some drivers do their own refcounting

		 * on vmalloc_to_page() pages, some use page->mapping,

		 * page->lru, etc.

		 */

		if (page_order)

			split_page(page, page_order);



		for (p = 0; p < (1U << page_order); p++)

			area->pages[i + p] = page + p;