From ae83c5eef59ffe6eb61110b8c8fd1ea3e0881712 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 25 Sep 2006 23:32:45 -0700 Subject: [PATCH] [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 Acked-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/power/snapshot.c | 62 +++++++++++++++++++++-------------------- 1 file changed, 32 insertions(+), 30 deletions(-) diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 591301ae8b7..979096c2777 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 */ -- 2.41.1