x86: cacheline_align tss_struct

The manual padding to align on cacheline size only worked in 32 bit
In 64 bit the structure was not aligned and contained wasted space.

use the compiler ____cachline_aligned to save space & properly align
this structure.

x86_64_default size goes from 9136 -> 8960
x86_64_AMD     size goes from 9136 -> 8896

built & running on 2.6.26-rc8.
Signed-off-by: NRichard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

include/asm-x86/processor.h

@@ -262,16 +262,12 @@ struct tss_struct {
 	unsigned long		io_bitmap_max;
 	struct thread_struct	*io_bitmap_owner;
 
-	/*
-	 * Pad the TSS to be cacheline-aligned (size is 0x100):
-	 */
-	unsigned long		__cacheline_filler[35];
 	/*
 	 * .. and then another 0x100 bytes for the emergency kernel stack:
 	 */
 	unsigned long		stack[64];
 
-} __attribute__((packed));
+} ____cacheline_aligned;
 
 DECLARE_PER_CPU(struct tss_struct, init_tss);