Provided by: likwid_4.3.3+dfsg1-1_amd64 bug


       likwid-perfctr - configure and read out hardware performance counters on x86 CPUs


       likwid-perfctr [-vhHmaief] [-c core_list] [-C core_list_for_pinning] [-g performance_group
       or   performance_event_string]   [-t   timeline_frequency]   [-S   monitoring_time]    [-T
       group_switch_frequency]  [-V  verbosity]  [-M access_mode] [-o output_file] [-s skip_mask]
       [-E search_str] [--stats]


       likwid-perfctr is a lightweight  command  line  application  to  configure  and  read  out
       hardware performance monitoring data on supported x86 processors. It can measure either as
       wrapper without changing the measured application or with marker API functions inside  the
       code,  which will turn on and off the counters. There are preconfigured performance groups
       with useful event sets and derived metrics. Additionally, arbitrary events can be measured
       with  custom event sets. The marker API can measure multiple named regions and the results
       are accumulated over multiple region calls.


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

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

       -H     prints group help message (use together with -g switch).

       -V <level>, --verbose <level>
              verbose  output  during  execution  for  debugging.  0  for  only  errors,  1   for
              informational output, 2 for detailed output and 3 for developer output

       -m     run in marker API mode

       -a     print available performance groups for current processor, then exit.

       -e     print available counters and performance events of current processor.

       -o, --output <filename>
              store  all  output  to  a  file  instead  of stdout. For the filename the following
              placeholders are supported: %j for PBS_JOBID, %r for MPI RANK (only  Intel  MPI  at
              the  moment),  %h  host  name  and  %p  for  process pid.  The placeholders must be
              separated by underscore as, e.g., -o test_%h_%p. You must specify a suffix  to  the
              filename. For txt the output is printed as is to the file. Other suffixes trigger a
              filter on the output.  Available filters are csv (comma separated values)  and  xml
              at the moment.

       -O     print     output     in     CSV     format    (conform    to    RFC    4180,    see
     for details).

       -i, --info
              print cpuid information about processor  and  about  Intel  Performance  Monitoring
              features, then exit.

       -c <cpu expression>
              specify  a  numerical  list  of  processors.  The  list may contain multiple items,
              separated by comma, and ranges. For example 0,3,9-11.

       -C <cpu expression>
              specify a numerical list of  processors.  The  list  may  contain  multiple  items,
              separated  by  comma,  and ranges. For example 0,3,9-11. This variant will also pin
              the threads to the cores. Also logical numberings can be used.

       -g, --group <performance group> or <performance event set string>
              specify which performance group to measure. This can be one of the tags output with
              the -a flag.  Also a custom event set can be specified by a comma separated list of
              events. Each event has the format eventId:register with the the register being  one
              of a architecture supported performance counter registers.

       -t <frequency of measurements>
              timeline  mode  for  time  resolved  measurements.  The  time unit must be given on
              command line, e.g. 4s, 500ms or 900us.

       -S <waittime between measurements>
              End-to-end measurement using likwid-perfctr  but  sleep  instead  of  executing  an
              application. The time unit must be given on command line, e.g. 4s, 500ms or 900us.

       -T <time between group switches>
              Frequency  to  switch  groups  if multiple are given on commandline, default is 2s.
              Value is ignored for a single event set and default frequency of  30s  is  used  to
              catch  overflows.  The  time  unit must be given on command line, e.g. 4s, 500ms or

       -s, --skip <mask>
              Specify skip mask as HEX number. For each  set  bit  the  corresponding  thread  is

       -f, --force
              Force writing of registers even if they are in use.

       -E <search_str>
              Print only events and corresponding counters matching <search_str>

              Always print statistics table


       Because  likwid-perfctr measures on processors and not single applications it is necessary
       to ensure that processes and threads are pinned to dedicated resources. You can either pin
       the application yourself or use the builtin pin functionality.

       1.  As wrapper with performance group:

       likwid-perfctr -C 0-2 -g TLB ./cacheBench -n 2 -l 1048576 -i 100 -t Stream

       The  parent  process  is  pinned  to  processor 0, Thread 0 to processor 1 and Thread 1 to
       processor 2.

       2.  As wrapper with custom event set on AMD:

       likwid-perfctr   -C    0-4    -g    INSTRUCTIONS_RETIRED_SSE:PMC0,CPU_CLOCKS_UNHALTED:PMC3

       It  is  specified  that the event INSTRUCTIONS_RETIRED_SSE is measured on counter PMC0 and
       the event CPU_CLOCKS_UNHALTED on counter PMC3.  It is possible calculate the run  time  of
       all  threads  based on the CPU_CLOCKS_UNHALTED event. If you want this you have to include
       this event in your custom event string as shown above.

       3.  As wrapper with custom event set on Intel:

       likwid-perfctr -C 0 -g INSTR_RETIRED_ANY:FIXC0,CPU_CLK_UNHALTED_CORE:FIXC1 ./stream-icc

       On  Intel  processors  fixed  events  are  measured  on  dedicated  counters.  These   are
       INSTR_RETIRED_ANY  and  CPU_CLK_UNHALTED_CORE.   If  you  configure  these fixed counters,
       likwid-perfctr will calculate the run time and CPI metrics for your run.

       4.  Using the marker API to measure only parts of your code (this can be  used  both  with
           groups or custom event sets):

       likwid-perfctr   -m   -C   0-4  -g  INSTRUCTIONS_RETIRED_SSE:PMC0,CPU_CLOCKS_UNHALTED:PMC3

       You have to link you code against and use the marker API calls.  Examples can
       be  found in examples folder /usr/share/likwid/examples.  The following code snippet shows
       the necessary calls:

       #include <likwid.h>

       /* only one thread calls init */

       /* Must be called by each thread the should
        * perform measurements.
        * If you place it in the same parallel
        * region as LIKWID_MARKER_START, perform a
        * barrier between the statements to avoid
        * timing problems.

       /* If you run the code region only once, register
        * the region tag previously to reduce the overhead
        * of START and STOP calls. Call it once for each
        * thread in parallel environment.
        * Note: No whitespace characters are allowed in the region tags
        * This call is optional, START will do the same operations.

       /* Start measurement
        * Note: No whitespace characters are allowed in the region tags
        * Your code to be measured is here
        * You can also nest named regions
        * No whitespaces are allowed in the region names!

       /* If you want to measure multiple groups/event sets
        * Switches through groups in round-robin fashion

       /* Finally */

       5.  Using likwid in timeline mode:

       likwid-perfctr -c 0-3 -g FLOPS_DP -t 300ms ./cacheBench > out.txt

       This will read out the counters every 300ms on physical cores 0-3 and write the results to
       out.txt.   The  application  is  not pinned to the CPUs. The output syntax of the timeline
       mode is for custom event sets:

       <groupID> <numberOfEvents> <numberOfThreads> <Timestamp> <Event1_Thread1> <Event2_Thread1>
       ... <Event1_Thread2> ... <EventN_ThreadM>

       For   performance  groups  with  metrics:  <groupID>  <numberOfMetrics>  <numberOfThreads>
       <Timestamp> <Metric1_Thread1> <Metric2_Thread1> ... <Metric1_Thread2> ...<MetricN_ThreadM>

       For timeline mode there is a frontend application likwid-perfscope(1), which enables  live
       plotting  of  selected  events.  Please  be aware that with high frequencies (<100ms), the
       values differ from the real results but the behavior of them is valid.

       6.  Using likwid in stethoscope mode:

       likwid-perfctr -c 0-3 -g FLOPS_DP -S 2s

       This will start the counters and read them out after 2s on physical cores  0-3  and  write
       the results to stdout.

       7.  Using likwid with counter options:

       likwid-perfctr -c S0:1@S1:1 -g LLC_LOOKUPS_DATA_READ:CBOX0C0:STATE=0x9 ./cacheBench

       This  will  program  the counter CBOX0C0 (the counter 0 of the LLC cache box 0) to measure
       the event LLC_LOOKUPS_DATA_READ and filter the increments by the  state  of  a  cacheline.
       STATE=0x9  for this event means all <invalid> and <modified> cachelines. Which options are
       allowed for which box is listed in LIKWID's html documentation. The values for the options
       can  be  found  in  the vendors performance monitoring documentations. Likwid measures the
       first CPU of socket 0 and the first  CPU  of  socket  1.  See  likwid-pin(1)  for  details
       regarding  the  cpu  expressions.   For  more code examples have a look at the likwid WIKI
       pages and LIKWID's html documentation.


       Written by Thomas Roehl <>.


       Report Bugs on <>.


       likwid-topology(1), likwid-perfscope(1), likwid-pin(1), likwid-bench(1)