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>

init/main.c

@@ -668,12 +668,12 @@ asmlinkage void __init start_kernel(void)
 #endif
 	thread_info_cache_init();
 	cred_init();
-	fork_init(num_physpages);
+	fork_init(totalram_pages);
 	proc_caches_init();
 	buffer_init();
 	key_init();
 	security_init();
-	vfs_caches_init(num_physpages);
+	vfs_caches_init(totalram_pages);
 	radix_tree_init();
 	signals_init();
 	/* rootfs populating might need page-writeback */