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Commit 6dbecfd3 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

PM / hibernate: Simplify mark_unsafe_pages() 



Rework mark_unsafe_pages() to use a simpler method of clearing
all bits in free_pages_map and to set the bits for the "unsafe"
pages (ie. pages that were used by the image kernel before
hibernation) with the help of duplicate_memory_bitmap().

For this purpose, move the pfn_valid() check from mark_unsafe_pages()
to unpack_orig_pfns() where the "unsafe" pages are discovered.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 9c744481

kernel/power/snapshot.c

+25 −39
Original line number Diff line number Diff line
@@ -2019,53 +2019,41 @@ int snapshot_read_next(struct snapshot_handle *handle) 
	return PAGE_SIZE;

}



static void duplicate_memory_bitmap(struct memory_bitmap *dst,

				    struct memory_bitmap *src)

{

	unsigned long pfn;



	memory_bm_position_reset(src);

	pfn = memory_bm_next_pfn(src);

	while (pfn != BM_END_OF_MAP) {

		memory_bm_set_bit(dst, pfn);

		pfn = memory_bm_next_pfn(src);

	}

}



/**

 *	mark_unsafe_pages - mark the pages that cannot be used for storing

 *	the image during resume, because they conflict with the pages that

 *	had been used before suspend

 */



static int mark_unsafe_pages(struct memory_bitmap *bm)

static void mark_unsafe_pages(struct memory_bitmap *bm)

{

	struct zone *zone;

	unsigned long pfn, max_zone_pfn;

	unsigned long pfn;



	/* Clear page flags */

	for_each_populated_zone(zone) {

		max_zone_pfn = zone_end_pfn(zone);

		for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)

			if (pfn_valid(pfn))

				swsusp_unset_page_free(pfn_to_page(pfn));

	/* Clear the "free"/"unsafe" bit for all PFNs */

	memory_bm_position_reset(free_pages_map);

	pfn = memory_bm_next_pfn(free_pages_map);

	while (pfn != BM_END_OF_MAP) {

		memory_bm_clear_current(free_pages_map);

		pfn = memory_bm_next_pfn(free_pages_map);

	}



	/* Mark pages that correspond to the "original" pfns as "unsafe" */

	memory_bm_position_reset(bm);

	do {

		pfn = memory_bm_next_pfn(bm);

		if (likely(pfn != BM_END_OF_MAP)) {

			if (likely(pfn_valid(pfn)))

				swsusp_set_page_free(pfn_to_page(pfn));

			else

				return -EFAULT;

		}

	} while (pfn != BM_END_OF_MAP);

	/* Mark pages that correspond to the "original" PFNs as "unsafe" */

	duplicate_memory_bitmap(free_pages_map, bm);



	allocated_unsafe_pages = 0;



	return 0;

}



static void

duplicate_memory_bitmap(struct memory_bitmap *dst, struct memory_bitmap *src)

{

	unsigned long pfn;



	memory_bm_position_reset(src);

	pfn = memory_bm_next_pfn(src);

	while (pfn != BM_END_OF_MAP) {

		memory_bm_set_bit(dst, pfn);

		pfn = memory_bm_next_pfn(src);

	}

}



static int check_header(struct swsusp_info *info)
@@ -2115,7 +2103,7 @@ static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm) 
		/* Extract and buffer page key for data page (s390 only). */

		page_key_memorize(buf + j);



		if (memory_bm_pfn_present(bm, buf[j]))

		if (pfn_valid(buf[j]) && memory_bm_pfn_present(bm, buf[j]))

			memory_bm_set_bit(bm, buf[j]);

		else

			return -EFAULT;
@@ -2357,9 +2345,7 @@ prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm) 
	buffer = NULL;



	nr_highmem = count_highmem_image_pages(bm);

	error = mark_unsafe_pages(bm);

	if (error)

		goto Free;

	mark_unsafe_pages(bm);



	error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);

	if (error)