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Date: Wed, 22 Jun 2016 03:19:45 +0200 From: "Rafael J. Wysocki" <rjw@...ysocki.net> To: Linux PM list <linux-pm@...r.kernel.org> Cc: Linux Kernel Mailing List <linux-kernel@...r.kernel.org> Subject: [PATCH] PM / hibernate: Simplify mark_unsafe_pages() From: Rafael J. Wysocki <rafael.j.wysocki@...el.com> Rework mark_unsafe_pages() to use a simpler method to clear 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: Rafael J. Wysocki <rafael.j.wysocki@...el.com> --- kernel/power/snapshot.c | 53 +++++++++++++++++++----------------------------- 1 file changed, 22 insertions(+), 31 deletions(-) Index: linux-pm/kernel/power/snapshot.c =================================================================== --- linux-pm.orig/kernel/power/snapshot.c +++ linux-pm/kernel/power/snapshot.c @@ -2049,6 +2049,19 @@ int snapshot_read_next(struct snapshot_h 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 @@ -2060,44 +2073,22 @@ static int mark_unsafe_pages(struct memo struct zone *zone; unsigned long pfn, max_zone_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) { char *reason; @@ -2145,7 +2136,7 @@ static int unpack_orig_pfns(unsigned lon /* 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;
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