diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/mmzone.c | 15 | ||||
| -rw-r--r-- | mm/vmstat.c | 19 |
2 files changed, 19 insertions, 15 deletions
diff --git a/mm/mmzone.c b/mm/mmzone.c index 16ce8b955dc..f5b7d176021 100644 --- a/mm/mmzone.c +++ b/mm/mmzone.c @@ -6,6 +6,7 @@ #include <linux/stddef.h> +#include <linux/mm.h> #include <linux/mmzone.h> #include <linux/module.h> @@ -72,3 +73,17 @@ struct zoneref *next_zones_zonelist(struct zoneref *z, *zone = zonelist_zone(z); return z; } + +#ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL +int memmap_valid_within(unsigned long pfn, + struct page *page, struct zone *zone) +{ + if (page_to_pfn(page) != pfn) + return 0; + + if (page_zone(page) != zone) + return 0; + + return 1; +} +#endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */ diff --git a/mm/vmstat.c b/mm/vmstat.c index 66f6130976c..74d66dba0cb 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -509,22 +509,11 @@ static void pagetypeinfo_showblockcount_print(struct seq_file *m, continue; page = pfn_to_page(pfn); -#ifdef CONFIG_ARCH_FLATMEM_HAS_HOLES - /* - * Ordinarily, memory holes in flatmem still have a valid - * memmap for the PFN range. However, an architecture for - * embedded systems (e.g. ARM) can free up the memmap backing - * holes to save memory on the assumption the memmap is - * never used. The page_zone linkages are then broken even - * though pfn_valid() returns true. Skip the page if the - * linkages are broken. Even if this test passed, the impact - * is that the counters for the movable type are off but - * fragmentation monitoring is likely meaningless on small - * systems. - */ - if (page_zone(page) != zone) + + /* Watch for unexpected holes punched in the memmap */ + if (!memmap_valid_within(pfn, page, zone)) continue; -#endif + mtype = get_pageblock_migratetype(page); if (mtype < MIGRATE_TYPES) |