> > You have a user-space program which parses /proc/cpuinfo instead of
> > executing CPUID itself, so it breaks.
>
> Arguably, it is always better to parse /proc/cpuinfo instead of executing
Actually this is definitively the case.
It is not safe to use cpuid to check the availability of RDTSC in Linux because
the CPU itself does not know if the TSC is buggy (Some MediaGX, some WinChip,..)
or if the TSC on an SMP box is constant across all processors.
Even checking the cpuinfo for the TSC should be done with care, and its far
far better to use gettimeofday unless doing very tiny timings (eg for
optimising code paths)
Alan
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Thu Nov 23 2000 - 21:00:12 EST