topic Hi Roman, in Software Tuning, Performance Optimization & Platform Monitoring

MSR access denied with pcm-memory.x

PAgra — Wed, 18 Nov 2015 16:16:21 GMT

Hello folks,

I'm trying the Intel PCM tools on the Mohon Peak CRB (ATOM Rangeley) and I'm facing a problem when I'm using the pcm-memory.x tool with an external program.

Here some logs:

[root@mohon_pag tmpd]# /usr/local/bin/pcm-memory.x -- /usr/sbin/send_frame_lin

Intel(r) Performance Counter Monitor: Memory Bandwidth Monitoring Utility V2.10 (2015-11-17 09:01:38 +0100 ID=cd66c34)

Copyright (c) 2009-2015 Intel Corporation
This utility measures memory bandwidth per channel or per DIMM rank in real-time

Number of logical cores: 8
Number of online logical cores: 1
Offlined cores: 1 2 3 4 5 6 7
Num sockets: 1
Physical cores per socket: 8
Core PMU (perfmon) version: 3
Number of core PMU generic (programmable) counters: 2
Width of generic (programmable) counters: 40 bits
Number of core PMU fixed counters: 3
Width of fixed counters: 40 bits
Nominal core frequency: 2400000000 Hz
Package thermal spec power: 0 Watt; Package minimum power: 0 Watt; Package maximum power: 0 Watt;
Access to Intel(r) Performance Counter Monitor has denied (no MSR or PCI CFG space access).
Cleaning up
[root@mohon_pag tmpd]# ls -als /dev/cpu/0/msr
0 crw-rw----. 1 root root 202, 0 Jan 13 06:15 /dev/cpu/0/msr
[root@mohon_pag tmpd]#

What could be the problem ?

Thanks.
Regards.

Patrick Agrain

Definitely pcm-memory tool is

Roman_D_Intel — Wed, 18 Nov 2015 16:25:49 GMT

Definitely pcm-memory tool is not supported on Atom (and memory metrics in pcm.x are also not supported on Atom). I wonder why there is no message that tells that.Does it appear if you online all cores?

Roman

Hi Roman,

PAgra — Thu, 19 Nov 2015 08:11:48 GMT

Hi Roman,

Thanks for the hint.

I was also wondering that the pcm tool does display any warning message this time. I was first trying it on an old product powered by a Pentium 3 processor and saw the message that this processor was not supported.

Unfortunately we can not use more than 1 core. Our application is very (very) old and was not written for SMP systems.

One thing remains:
From https://software.intel.com/en-us/articles/intel-performance-counter-monitor
<...>
Version 2.6:

Support for Intel® Xeon® E5 v2 processor series (microarchitecture previously codenamed Ivybridge-EP)
Support for Intel® Core™ i5-4350U (microarchitecture previously codenamed Haswell ULT)
Support for Intel® Atom™ processor C2000 series (microarchitecture previously codenamed Avoton)
Support for Intel® Atom™ processor Z3000 series (microarchitecture previously codenamed Baytrail)
Support API for programming “off-core response” PMU events. A usage example is in the new pcm-numa utility.
Bug fixes

What indeed is then suported for the Atom Rangeley C2338 ?

Regards,

Patrick Agrain

For Atom, PCM supports

Roman_D_Intel — Thu, 19 Nov 2015 10:19:04 GMT

For Atom, PCM supports instruction per cycle, cache metrics, energy consumption metrics, C state residency, etc. You can see them in pcm.x output.

Roman