[PATCH] x86-64: Fix bad assumption that dualcore cpus have synced TSCs

This should resolve the issue seen in bugme bug #5105, where it is assumed
that dualcore x86_64 systems have synced TSCs.  This is not the case, and
alternate timesources should be used instead.

For more details, see:
http://bugzilla.kernel.org/show_bug.cgi?id=5105

Andi's earlier concerns that the TSCs should be synced on dualcore systems
have been resolved by confirmation from AMD folks that they can be
unsynced.
Acked-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

arch/x86_64/kernel/time.c

@@ -959,9 +959,6 @@ static __init int unsynchronized_tsc(void)
  	   are handled in the OEM check above. */
  	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
  		return 0;
- 	/* All in a single socket - should be synchronized */
- 	if (cpus_weight(cpu_core_map[0]) == num_online_cpus())
- 		return 0;
 #endif
  	/* Assume multi socket systems are not synchronized */
  	return num_online_cpus() > 1;