[PATCH] arm: add comment about max_low_pfn/max_pfn

)


From: Russell King <rmk+lkml@arm.linux.org.uk>

Oddly, max_low_pfn/max_pfn end up being the number of pages in the system,
rather than the maximum PFN on ARM.  This doesn't seem to cause any problems,
so just add a note about it.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/arm/mm/init.c

@@ -223,6 +223,9 @@ find_memend_and_nodes(struct meminfo *mi, struct node_info *np)
 	 * This doesn't seem to be used by the Linux memory
 	 * manager any more.  If we can get rid of it, we
 	 * also get rid of some of the stuff above as well.
+	 *
+	 * Note: max_low_pfn and max_pfn reflect the number
+	 * of _pages_ in the system, not the maximum PFN.
 	 */
 	max_low_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET);
 	max_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET);