|
NAME | SYNOPSIS | DESCRIPTION | MODIFIERS | OFFCORE_RESPONSE events | AUTHORS | COLOPHON |
LIBPFM(3) Linux Programmer's Manual LIBPFM(3)
libpfm_intel_tmt - support for Intel Tremont core PMU
#include <perfmon/pfmlib.h>
PMU name: tmt
PMU desc: Intel Tremont
The library supports the Intel Tremont core PMU.
The following modifiers are supported on Intel Tremont 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].
Intel Tremont provides two offcore_response events:
OFFCORE_RESPONSE_0 and OFFCORE_RESPONSE_1. The OCR event is aliased
to OFFCORE_RESPONSE_0.
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 kernel needs to manage the sharing of
that extra register.
The offcore_response event is exposed as a normal event by the
library. The extra settings are exposed as regular umasks. The
library takes care of encoding the events according for the
underlying kernel interface.
On Intel Tremont, it is not possible to combine the request,
supplier, snoop, fields anymore to avoid invalid combinations. As
such, the umasks provided by the library are the only ones supported
and validated.
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
March, 2020 LIBPFM(3)