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)