Re: [RT] read_tsc: ACK! TSC went backward! Unsynced TSCs?

Lee Revell
2005-11-28T17:52:00Z

On Mon, 2005-11-28 at 09:30 -0800, thockin@hockin.org wrote:
> The kernel's use of TSC is wholly incorrect. TSCs can ramp up and
> down and *do* vary between nodes as well as between cores within a
> node. You really can not compare TSCs between cpu cores at all, as is
> (and the kernel assumes 1 global TSC in at least a few places).

That's one way to look at it; another is that the AMD dual cores have a
broken TSC implementation. The kernel's use of the TSC was never a
problem in the past...

Lee