Alan Cox writes:
> On Thu, 2002-08-15 at 17:56, Andrea Arcangeli wrote:
> > sorry but I don't see the point of badtsc only in kernel.
> >
> > If the TSC is bad that will be in particular bad from userspace where
> > there's no hope to know what CPU you're running on.
>
> You can still do meaningful measurements for things like profiling
> because the cpu hop is statistically uninteresting.
There are kernel extensions around that handle process migration across
CPUs while providing virtualised per-process TSC counts, and for which
the TSCs do NOT need to be in perfect sync.
Disabling user-space RDTSC just because the TSCs aren't in sync is stupid.
/Mikael
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This archive was generated by hypermail 2b29 : Fri Aug 23 2002 - 22:00:12 EST