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authorRafael J. Wysocki <rjw@sisk.pl>2006-09-25 23:32:45 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-09-26 08:48:58 -0700
commitae83c5eef59ffe6eb61110b8c8fd1ea3e0881712 (patch)
tree731e4d382ff408387624df1fc59e82ab50436f50 /kernel
parent546e0d271941dd1ff6961e2a1f7eac75f1fc277e (diff)
downloadlwn-ae83c5eef59ffe6eb61110b8c8fd1ea3e0881712.tar.gz
lwn-ae83c5eef59ffe6eb61110b8c8fd1ea3e0881712.zip
[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: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/power/snapshot.c62
1 files changed, 32 insertions, 30 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 591301ae8b7d..979096c27773 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -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 */