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  hardware  thread.   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 hardware threads 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 Gruber <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)