KNC

Architecture specific notes for Intel® Xeon Phi

If you want to use LIKWID on a Xeon Phi you have to use set MIC as COMPILER in config.mk. This build of LIKWID will not be binary compatible with other X86 processors. To use LIKWID you have to turn of power management on the MIC. LIKWID relies on RDTSC being used for wallclock time. On the MIC this is only given if power management is turned off. This can be configured in /etc/sysconfig/mic/default.conf. Moreover, you have to set the RPATH variable in make/include_MIC.mk to point to the Intel libraries libimf.so, libiomp*.so. Since the likwid-lua executable needs to be set suid-root, the LD_LIBRARY_PATH is ignored at its startup. Also the executable that should be measured with likwid-perfctr must have correct rpath settings.

At the end of this file the power management is configured. The following configuration worked:

PowerManagement "cpufreq_off;corec6_off;pc3_off;pc6_off"

Performance groups

Intel® Xeon Phi Performance groups

Events

The input file for the events on Intel® Xeon Phi can be found here.

Counters

• Core-local counters
  • General-purpose counters

Core-local counters

General-purpose counters

The Intel® Xeon Phi microarchitecture provides 2 general-purpose counters consisting of a config and a counter register.

Counters

Counter name	Event name
PMC0	*
PMC1	*

##### Available Options

Option	Argument	Description	Comment
edgedetect	N	Set bit 18 in config register
kernel	N	Set bit 17 in config register
anythread	N	Set bit 21 in config register
threshold	8 bit hex value	Set bits 24-31 in config register
invert	N	Set bit 23 in config register