[PATCH] x86-64: Fix bad assumption that dualcore cpus have syncedTSCs (resend)

[john stultz]

Andrew,
	This patch 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.

Please consider for inclusion in your tree.

thanks
-john

diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -959,9 +959,6 @@ static __init int unsynchronized_tsc(voi
  	   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;


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/