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NAME | SYNOPSIS | DESCRIPTION | MODIFIERS | OFFCORE_RESPONSE events | AUTHORS | COLOPHON |
LIBPFM(3) Linux Programmer's Manual LIBPFM(3)
libpfm_intel_icl - support for Intel IceLake core PMU
#include <perfmon/pfmlib.h>
PMU name: icl
PMU desc: Intel IceLake
The library supports the Intel IceLake core PMU. It should be noted
that this PMU model only covers each core's PMU and not the socket
level PMU.
On IceLake, the number of generic counters depends on the
Hyperthreading (HT) mode.
The pfm_get_pmu_info() function returns the maximum number of generic
counters in num_cntrs.
The following modifiers are supported on Intel IceLake processors:
u Measure at user level which includes privilege levels 1, 2, 3.
This corresponds to PFM_PLM3. This is a boolean modifier.
k Measure at kernel level which includes privilege level 0. This
corresponds to PFM_PLM0. This is a boolean modifier.
i Invert the meaning of the event. The counter will now count
cycles in which the event is not occurring. This is a boolean
modifier
e Enable edge detection, i.e., count only when there is a state
transition from no occurrence of the event to at least one
occurrence. This modifier must be combined with a counter mask
modifier (m) with a value greater or equal to one. This is a
boolean modifier.
c Set the counter mask value. The mask acts as a threshold. The
counter will count the number of cycles in which the number of
occurrences of the event is greater or equal to the threshold.
This is an integer modifier with values in the range [0:255].
ldlat Pass a latency threshold to the MEM_TRANS_RETIRED:LOAD_LATENCY
event. This is an integer attribute that must be in the range
[3:65535]. It is required for this event. Note that the event
must be used with precise sampling (PEBS).
intx Monitor the event only when executing inside a transactional
memory region (in tx). Event does not count otherwise. This is
a boolean modifiers. Default value is 0.
intxcp Do not count occurrences of the event when they are inside an
aborted transactional memory region. This is a boolean
modifier. Default value is 0.
fe_thres
This modifier is for the FRONTEND_RETIRED event only. It
defines the period in core cycles after which the
IDQ_*_BUBBLES umask counts. It acts as a threshold, i.e., at
least a period of N core cycles where the frontend did not
deliver X uops. It can only be used with the IDQ_*_BUBBLES
umasks. If not specified, the default threshold value is 1
cycle. the valid values are in [1-4095].
Intel IceLake supports two encodings for offcore_response events. In
the library, these are called OFFCORE_RESPONSE_0 and
OFFCORE_RESPONSE_1.
Those events need special treatment in the performance monitoring
infrastructure because each event uses an extra register to store
some settings. Thus, in case multiple offcore_response events are
monitored simultaneously, the operating system needs to manage the
sharing of that extra register.
The offcore_response events are exposed as a normal events by the
library. The extra settings are exposed as regular umasks. The
library takes care of encoding the events according to the underlying
kernel interface.
On Intel IceLake unlike older processors, the event is treated as a
regular event with a flat set of umasks to choose from. It is not
possible to combine the various requests, supplier, snoop bits
anymore. Therefore the library offers the list of validated
combinations as per Intel's official event list.
Stephane Eranian <eranian@gmail.com>
This page is part of the perfmon2 (a performance monitoring library)
project. Information about the project can be found at
⟨http://perfmon2.sourceforge.net/⟩. If you have a bug report for this
manual page, send it to perfmon2-devel@lists.sourceforge.net. This
page was obtained from the project's upstream Git repository
⟨git://git.code.sf.net/p/perfmon2/libpfm4 perfmon2-libpfm4⟩ on
2020-08-13. (At that time, the date of the most recent commit that
was found in the repository was 2020-08-12.) If you discover any
rendering problems in this HTML version of the page, or you believe
there is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
August, 2015 LIBPFM(3)