es in the memmap. Rather than an expensive check for valid memory, /proc/pagetypeinfo will confirm that the page linkages are still valid by checking page->zone is still the expected zone. The lookup of page_zone is safe as there is a limited range of memory that is accessed when calling page_zone. Even if page_zone happens to return the correct zone, the impact is that the counters in /proc/pagetypeinfo are slightly off but fragmentation monitoring is unlikely to be relevant on an embedded system. Reported-by: H Hartley Sweeten Signed-off-by: Mel Gorman Tested-by: H Hartley Sweeten Signed-off-by: Russell King —Ý-Z”