Unverified Commit 543ee9f8 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!1246 mm/hugetlb_vmemmap: remap head page to newly allocated page 

Merge Pull Request from: @ci-robot 
 
PR sync from: Liu Shixin <liushixin2@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/5RIDEB6A7NBTUWJUHQL6MOC4ZUD2N323/ 
 
 
Link:https://gitee.com/openeuler/kernel/pulls/1246

 

Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parents 6eb8fb4a 4aae6225

mm/sparse-vmemmap.c

+34 −7
Original line number Diff line number Diff line
@@ -221,12 +221,7 @@ static int vmemmap_remap_range(unsigned long start, unsigned long end, 
			return ret;

	} while (pgd++, addr = next, addr != end);



	/*

	 * We only change the mapping of the vmemmap virtual address range

	 * [@start + PAGE_SIZE, end), so we only need to flush the TLB which

	 * belongs to the range.

	 */

	flush_tlb_kernel_range(start + PAGE_SIZE, end);

	flush_tlb_kernel_range(start, end);



	return 0;

}
@@ -264,9 +259,23 @@ static void vmemmap_remap_pte(pte_t *pte, unsigned long addr, 
	 * to the tail pages.

	 */

	pgprot_t pgprot = PAGE_KERNEL_RO;

	pte_t entry = mk_pte(walk->reuse_page, pgprot);

	struct page *page = pte_page(*pte);

	pte_t entry;



	/* Remapping the head page requires r/w */

	if (unlikely(addr == walk->reuse_addr)) {

		pgprot = PAGE_KERNEL;

		list_del(&walk->reuse_page->lru);



		/*

		 * Makes sure that preceding stores to the page contents from

		 * vmemmap_remap_free() become visible before the set_pte_at()

		 * write.

		 */

		smp_wmb();

	}



	entry = mk_pte(walk->reuse_page, pgprot);

	list_add_tail(&page->lru, walk->vmemmap_pages);

	set_pte_at(&init_mm, addr, pte, entry);

}
@@ -331,6 +340,24 @@ int vmemmap_remap_free(unsigned long start, unsigned long end, 
		.reuse_addr	= reuse,

		.vmemmap_pages	= &vmemmap_pages,

	};

	int nid = page_to_nid((struct page *)start);

	gfp_t gfp_mask = GFP_KERNEL | __GFP_THISNODE | __GFP_NORETRY |

			__GFP_NOWARN;



	/*

	 * Allocate a new head vmemmap page to avoid breaking a contiguous

	 * block of struct page memory when freeing it back to page allocator

	 * in free_vmemmap_page_list(). This will allow the likely contiguous

	 * struct page backing memory to be kept contiguous and allowing for

	 * more allocations of hugepages. Fallback to the currently

	 * mapped head page in case should it fail to allocate.

	 */

	walk.reuse_page = alloc_pages_node(nid, gfp_mask, 0);

	if (walk.reuse_page) {

		copy_page(page_to_virt(walk.reuse_page),

			  (void *)walk.reuse_addr);

		list_add(&walk.reuse_page->lru, &vmemmap_pages);

	}



	/*

	 * In order to make remapping routine most efficient for the huge pages,