On 04/19/2010 01:59 PM, Peter Zijlstra wrote:
So what do we need? test for both TSC_RELIABLE and NONSTOP_TSC? IMO
TSC_RELIABLE should imply NONSTOP_TSC.
Yeah, I think RELIABLE does imply NONSTOP and CONSTANT, but NONSTOP&&
CONSTANT does not make RELIABLE.
The manual says:
16.11.1 Invariant TSC
The time stamp counter in newer processors may support an enhancement,
referred
to as invariant TSC. Processor’s support for invariant TSC is indicated by
CPUID.80000007H:EDX[8].
The invariant TSC will run at a constant rate in all ACPI P-, C-. and
T-states. This is
the architectural behavior moving forward. On processors with
invariant TSC
support, the OS may use the TSC for wall clock timer services (instead
of ACPI or
HPET timers). TSC reads are much more efficient and do not incur the
overhead
associated with a ring transition or access to a platform resource.
and this maps to NONSTOP, so I think we're fine.
--
error compiling committee.c: too many arguments to function
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