Messages in this thread | | | Date | Tue, 22 Nov 2005 21:52:00 +0100 | From | Ingo Molnar <> | Subject | Re: test time-warps [was: Re: 2.6.14-rt13] |
| |
* Steven Rostedt <rostedt@goodmis.org> wrote:
> > > Apparently that's the case. > > > > What about periodically re-syncing the TSCs on the cpus? Are they > > writeable? > > I believe you can reset them to zero, but I don't think you can set > them to anything else. I had to do something similar a few years ago, > and I don't have the specs in front of me, so this is coming straight > from memory.
on a reasonably new CPU you ought to be able to set the 64-bit value - but that doesnt change the fundamental fact: we have no idea how much time has passed while we were in HLT. Especially with things like dyntick/noidle we could spend _alot_ of time in HLT, and the TSC could drift significantly. How do we know how much that is?
Ingo - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |