поддержка Intel Silvermont core PMU (support for Intel Silvermont core PMU)
Имя (Name)
libpfm_intel_slm - support for Intel Silvermont core PMU
Синопсис (Synopsis)
#include <perfmon/pfmlib.h>
PMU name: slm
PMU desc: Intel Silvermont
Описание (Description)
The library supports the Intel Silvermont core PMU.
Модификаторы (Modifiers)
The following modifiers are supported on Intel Silvermont
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].
Cобытия отклика вне ядра (Offcore_response events)
Intel Silvermont provides two offcore_response events:
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 kernel needs to manage the sharing
of that extra register.
The offcore_response events are 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 to the
underlying kernel interface.
On Intel Silvermont, the umasks are divided into three
categories: request, supplier and snoop. The user must provide at
least one umask for each category. The categories are shown in
the umask descriptions. The library provides a default umask per
category if not provided by the user.
There is also the special response umask called ANY_RESPONSE.
When this umask is used then it overrides any supplier and snoop
umasks. In other words, users can specify either ANY_RESPONSE OR
any combinations of supplier + snoops.
In case no supplier or snoop is specified, the library defaults
to using ANY_RESPONSE.
For instance, the following are valid event selections:
OFFCORE_RESPONSE_0:DMND_DATA_RD:ANY_RESPONSE
OFFCORE_RESPONSE_0:ANY_REQUEST
OFFCORE_RESPONSE_0:ANY_RFO:LLC_HITM:SNOOP_ANY
But the following are illegal:
OFFCORE_RESPONSE_0:ANY_RFO:NON_DRAM:ANY_RESPONSE
OFFCORE_RESPONSE_0:ANY_RFO:L2_HIT:SNOOP_ANY:ANY_RESPONSE
