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Commit ae83c5ee authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
Browse files

[PATCH] swsusp: clean up browsing of pfns 



Clean up some loops over pfns for each zone in snapshot.c: reduce the
number of additions to perform, rework detection of saveable pages and make
the code a bit less difficult to understand, hopefully.

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 546e0d27

kernel/power/snapshot.c

+32 −30
Original line number Diff line number Diff line
@@ -156,7 +156,7 @@ static inline int save_highmem(void) {return 0;} 
static inline int restore_highmem(void) {return 0;}

#endif



static int pfn_is_nosave(unsigned long pfn)

static inline int pfn_is_nosave(unsigned long pfn)

{

	unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;

	unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT;
@@ -167,43 +167,43 @@ static int pfn_is_nosave(unsigned long pfn) 
 *	saveable - Determine whether a page should be cloned or not.

 *	@pfn:	The page

 *

 *	We save a page if it's Reserved, and not in the range of pages

 *	statically defined as 'unsaveable', or if it isn't reserved, and

 *	isn't part of a free chunk of pages.

 *	We save a page if it isn't Nosave, and is not in the range of pages

 *	statically defined as 'unsaveable', and it

 *	isn't a part of a free chunk of pages.

 */



static int saveable(struct zone *zone, unsigned long *zone_pfn)

static struct page *saveable_page(unsigned long pfn)

{

	unsigned long pfn = *zone_pfn + zone->zone_start_pfn;

	struct page *page;



	if (!pfn_valid(pfn))

		return 0;

		return NULL;



	page = pfn_to_page(pfn);

	BUG_ON(PageReserved(page) && PageNosave(page));



	if (PageNosave(page))

		return 0;

		return NULL;

	if (PageReserved(page) && pfn_is_nosave(pfn))

		return 0;

		return NULL;

	if (PageNosaveFree(page))

		return 0;

		return NULL;



	return 1;

	return page;

}



unsigned int count_data_pages(void)

{

	struct zone *zone;

	unsigned long zone_pfn;

	unsigned long pfn, max_zone_pfn;

	unsigned int n = 0;



	for_each_zone (zone) {

		if (is_highmem(zone))

			continue;

		mark_free_pages(zone);

		for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)

			n += saveable(zone, &zone_pfn);

		max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;

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

			n += !!saveable_page(pfn);

	}

	return n;

}
@@ -211,7 +211,7 @@ unsigned int count_data_pages(void) 
static void copy_data_pages(struct pbe *pblist)

{

	struct zone *zone;

	unsigned long zone_pfn;

	unsigned long pfn, max_zone_pfn;

	struct pbe *pbe, *p;



	pbe = pblist;
@@ -224,13 +224,14 @@ static void copy_data_pages(struct pbe *pblist) 
			SetPageNosaveFree(virt_to_page(p));

		for_each_pbe (p, pblist)

			SetPageNosaveFree(virt_to_page(p->address));

		for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {

			if (saveable(zone, &zone_pfn)) {

				struct page *page;

		max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;

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

			struct page *page = saveable_page(pfn);



			if (page) {

				long *src, *dst;

				int n;



				page = pfn_to_page(zone_pfn + zone->zone_start_pfn);

				BUG_ON(!pbe);

				pbe->orig_address = (unsigned long)page_address(page);

				/* copy_page and memcpy are not usable for copying task structs. */
@@ -383,13 +384,14 @@ static struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask, 
void swsusp_free(void)

{

	struct zone *zone;

	unsigned long zone_pfn;

	unsigned long pfn, max_zone_pfn;



	for_each_zone(zone) {

		for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)

			if (pfn_valid(zone_pfn + zone->zone_start_pfn)) {

				struct page *page;

				page = pfn_to_page(zone_pfn + zone->zone_start_pfn);

		max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;

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

			if (pfn_valid(pfn)) {

				struct page *page = pfn_to_page(pfn);



				if (PageNosave(page) && PageNosaveFree(page)) {

					ClearPageNosave(page);

					ClearPageNosaveFree(page);
@@ -598,7 +600,7 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count) 
static int mark_unsafe_pages(struct pbe *pblist)

{

	struct zone *zone;

	unsigned long zone_pfn;

	unsigned long pfn, max_zone_pfn;

	struct pbe *p;



	if (!pblist) /* a sanity check */
@@ -606,10 +608,10 @@ static int mark_unsafe_pages(struct pbe *pblist) 


	/* Clear page flags */

	for_each_zone (zone) {

		for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)

			if (pfn_valid(zone_pfn + zone->zone_start_pfn))

				ClearPageNosaveFree(pfn_to_page(zone_pfn +

					zone->zone_start_pfn));

		max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;

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

			if (pfn_valid(pfn))

				ClearPageNosaveFree(pfn_to_page(pfn));

	}



	/* Mark orig addresses */