Re: [patch] x86: unify/rewrite SMP TSC sync code

From: Christoph Lameter
Date: Mon Nov 27 2006 - 14:01:26 EST


On Fri, 24 Nov 2006, Andi Kleen wrote:

> The trouble is that people are using the RDTSC anyways even if the
> kernel doesn't. So some synchronization is probably a good idea.

It is better to simply leave TSC alone if unsynchronized. If TSCs appear
to be in sync (through some sporadic "synchronization") then people will
be tempted to use RDTSC because it seems to work/ However, RDTSC will
sporadically yield incoherent values (i.e. time earlier than last TSC
read) if we have no full synchronization.
-
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/