NAME

       likwid-features - print and manipulate cpu features like hardware prefetchers (Intel only)

SYNOPSIS

       likwid-features [-vhal] [-c cpus] [-e taglist] [-d taglist]

DESCRIPTION

       likwid-features  is  a  command  line application to print the flags in the model specific register (MSR)
       MSR_IA32_MISC_ENABLE on Intel x86 processors. On Core2 and later processors it can be used to toggle  the
       hardware  prefetch  flags.  It  does  not  work  on  AMD  processors.  For a documentation what flags are
       supported on which processor refer to the Intel Software Developer's Manual  Volume  3B,  Table  B.2  and
       https://software.intel.com/en-us/articles/disclosure-of-hw-prefetcher-control-on-some-intel-processors.
       The MSR are set individually for every core.  The following hardware prefetchers can be toggled:

       •      HW_PREFETCHER: Hardware prefetcher.

       •      CL_PREFETCHER: Adjacent cache line prefetcher.

       •      DCU_PREFETCHER: When the DCU prefetcher detects multiple loads from the same line  done  within  a
              time limit, the DCU prefetcher assumes the next line will be required. The next line is prefetched
              in to the L1 data cache from memory or L2.

       •      IP_PREFETCHER: The IP prefetcher is an L1 data cache  prefetcher.  The  IP  prefetcher  looks  for
              sequential  load history to determine whether to prefetch the next expected data into the L1 cache
              from memory or L2.

OPTIONS

       -v     prints version information to standard output, then exits.

       -h     prints a help message to standard output, then exits.

       -a     List out the names of all detected features

       -l     Print the state of all features for the given CPUs

       -c  cpus
              set on which processor cores the MSR should be read and written. Syntax according to likwid-pin(1)

       -d  HW_PREFETCHER | CL_PREFETCHER | DCU_PREFETCHER | IP_PREFETCHER
              specify which prefetcher should be disabled. Argument can be a comma-separated list.

       -e  HW_PREFETCHER | CL_PREFETCHER | DCU_PREFETCHER | IP_PREFETCHER
              specify which prefetcher should be enabled. Argument can be a comma-separated list.

AUTHOR

       Written by Thomas Röhl <thomas.Roehl@gmail.com>.

BUGS

       Report Bugs on <https://github.com/RRZE-HPC/likwidissues>.

SEE ALSO

       likwid-pin(1), likwid-topology(1), likwid-perfctr(1)