mm: replace various uses of num_physpages by totalram_pages

Sizing of memory allocations shouldn't depend on the number of physical
pages found in a system, as that generally includes (perhaps a huge amount
of) non-RAM pages.  The amount of what actually is usable as storage
should instead be used as a basis here.

Some of the calculations (i.e.  those not intending to use high memory)
should likely even use (totalram_pages - totalhigh_pages).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/agp/backend.c b/drivers/char/agp/backend.c
index ad87753..a56ca08 100644
--- a/drivers/char/agp/backend.c
+++ b/drivers/char/agp/backend.c
@@ -114,9 +114,9 @@
 	long memory, index, result;
 
 #if PAGE_SHIFT < 20
-	memory = num_physpages >> (20 - PAGE_SHIFT);
+	memory = totalram_pages >> (20 - PAGE_SHIFT);
 #else
-	memory = num_physpages << (PAGE_SHIFT - 20);
+	memory = totalram_pages << (PAGE_SHIFT - 20);
 #endif
 	index = 1;