mm: skip memory block registration for ZONE_DEVICE
Prevent userspace from trying and failing to online ZONE_DEVICE pages
which are meant to never be onlined.
For example on platforms with a udev rule like the following:
SUBSYSTEM=="memory", ACTION=="add", ATTR{state}=="offline", ATTR{state}="online"
...will generate futile attempts to online the ZONE_DEVICE sections.
Example kernel messages:
Built 1 zonelists in Node order, mobility grouping on. Total pages: 1004747
Policy zone: Normal
online_pages [mem 0x248000000-0x24fffffff] failed
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0ef5f21..d9fe12d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -674,6 +674,18 @@
return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
}
+#ifdef CONFIG_ZONE_DEVICE
+static inline bool is_zone_device_page(const struct page *page)
+{
+ return page_zonenum(page) == ZONE_DEVICE;
+}
+#else
+static inline bool is_zone_device_page(const struct page *page)
+{
+ return false;
+}
+#endif
+
#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
#define SECTION_IN_PAGE_FLAGS
#endif