ZONE_PADDING wastes 4 bytes of the new cacheline

Andrea Arcangeli
2004-10-21T01:29:57Z

I don't see why this 'int x' exists, alignment should really work fine
even with empty structure (works with my compiler with an userspace
test, please double check).

Index: linux-2.5/include/linux/mmzone.h
===================================================================
RCS file: /home/andrea/crypto/cvs/linux-2.5/include/linux/mmzone.h,v
retrieving revision 1.67
diff -u -p -r1.67 mmzone.h
--- linux-2.5/include/linux/mmzone.h 19 Oct 2004 14:58:00 -0000 1.67
+++ linux-2.5/include/linux/mmzone.h 21 Oct 2004 01:14:20 -0000
@@ -35,7 +35,6 @@ struct pglist_data;
*/
#if defined(CONFIG_SMP)
struct zone_padding {
- int x;
} ____cacheline_maxaligned_in_smp;
#define ZONE_PADDING(name) struct zone_padding name;
#else