System.LibCPUID

Bindings to https://github.com/anrieff/libcpuid.

Currently implemented:

• getting CPU vendor and brand strings, TSC availability, number of physical, and logical cores
• measuring CPU clock frequency using a time-stamp counter and time intervals
• getting CPU clock frequency as reported by the OS
• measuring CPU clock frequency using a busy-wait cycle

LibCPUID utilities

getTotalLogicalCores :: IO Int

Get the total number of logical cores (even if CPUID is not present). If CPUID is present, the following is true:

• getTotalLogicalCores = totalLogicalCores <$> cpuid

clockByOS :: IO Int

Get the CPU clock frequency in MHz, as reported by the OS (which may differ from the true clock). If the OS is not supported, the result will be -1.

clockMeasure :: Int -> ShouldQuadCheck -> IO Int

Get the CPU clock frequency in MHz, after performing a busy-wait cycle for the given time in ms. If RDTSC is not supported, the result will be -1.

newtype ShouldQuadCheck

Should clockMeasure do a more thorough measurement (quadruple checking).

Constructors

ShouldQuadCheck Bool

clock :: IO Int

Get the CPU clock frequency in MHz, by trying all available methods. If all of them fail, the result will be -1.

Reexports from System.LibCPUID.CPUID

data CPUID

CPU information and features.

Constructors

CPUID

Fields

• vendorString :: String

  CPU vendor string, e.g. "GenuineIntel".

• brandString :: String

  CPU brand string, e.g. "Intel(R) Core(TM) i5-7500 CPU @ 3.40GHz".

• hasTSC :: Bool

  Is a time-stamp counter available.

• physicalCores :: Int

  Number of physical cores per processor.

• logicalCores :: Int

  Number of logical cores per processor.

• totalLogicalCores :: Int

  Total number of logical cores, which is logicalCores multiplied by the number of processors.

Instances

Storable CPUID

Defined in System.LibCPUID.CPUID

Methods

sizeOf :: CPUID -> Int

alignment :: CPUID -> Int

peekElemOff :: Ptr CPUID -> Int -> IO CPUID

pokeElemOff :: Ptr CPUID -> Int -> CPUID -> IO ()

peekByteOff :: Ptr b -> Int -> IO CPUID

pokeByteOff :: Ptr b -> Int -> CPUID -> IO ()

peek :: Ptr CPUID -> IO CPUID

poke :: Ptr CPUID -> CPUID -> IO ()

cpuid :: IO (Either String CPUID)

Get CPU information and features, or an error message, if the CPU can't be identified by libcpuid.

Reexports from System.LibCPUID.TSC

data TSCMark

initialise :: IO TSCMark

Initialise a TSCMark.

mark :: TSCMark -> IO ()

Mark a time interval for calculating the CPU clock frequency.

unmark :: TSCMark -> IO ()

Unmark a time interval for calculating the CPU clock frequency.

clockBy :: TSCMark -> IO Int

Calculate the CPU clock frequency in MHz, for an interval, marked with mark, and unmark. If the interval is insufficient, the result will be -1.