1LIBPFM(3)                  Linux Programmer's Manual                 LIBPFM(3)
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NAME

6       libpfm_intel_bdw - support for Intel Broadwell core PMU
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SYNOPSIS

9       #include <perfmon/pfmlib.h>
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11       PMU name: bdw
12       PMU desc: Intel Broadwell
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DESCRIPTION

16       The  library  supports the Intel Broadwell core PMU. It should be noted
17       that this PMU model only covers each core's  PMU  and  not  the  socket
18       level PMU.
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20       On  Broadwell,  the  number  of  generic counters depends on the Hyper‐
21       threading (HT) mode.  When HT is on, then only 4 generic  counters  are
22       available.  When  HT is off, then 8 generic counters are available. The
23       pfm_get_pmu_info() function returns the maximum number of generic coun‐
24       ters in num_cntrs.
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MODIFIERS

28       The following modifiers are supported on Intel Broadwell processors:
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30       u      Measure  at  user level which includes privilege levels 1, 2, 3.
31              This corresponds to PFM_PLM3.  This is a boolean modifier.
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33       k      Measure at kernel level which includes privilege level  0.  This
34              corresponds to PFM_PLM0.  This is a boolean modifier.
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36       i      Invert  the meaning of the event. The counter will now count cy‐
37              cles in which the event is not occurring. This is a boolean mod‐
38              ifier
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40       e      Enable  edge  detection,  i.e., count only when there is a state
41              transition from no occurrence of the event to at least  one  oc‐
42              currence.  This  modifier  must  be combined with a counter mask
43              modifier (m) with a value greater or equal to one.   This  is  a
44              boolean modifier.
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46       c      Set  the  counter  mask value. The mask acts as a threshold. The
47              counter will count the number of cycles in which the  number  of
48              occurrences  of  the event is greater or equal to the threshold.
49              This is an integer modifier with values in the range [0:255].
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51       t      Measure on both threads at the same time assuming  hyper-thread‐
52              ing is enabled. This is a boolean modifier.
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54       ldlat  Pass  a  latency threshold to the MEM_TRANS_RETIRED:LOAD_LATENCY
55              event.  This is an integer attribute that must be in  the  range
56              [1:65535].  It  is required for this event.  Note that the event
57              must be used with precise sampling (PEBS).
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59       intx   Monitor the event only when  executing  inside  a  transactional
60              memory region (in tx). Event does not count otherwise. This is a
61              boolean modifiers. Default value is 0.
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63       intxcp Do not count occurrences of the event when they  are  inside  an
64              aborted transactional memory region. This is a boolean modifier.
65              Default value is 0.
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OFFCORE_RESPONSE events

69       Intel Broadwell provides two offcore_response events. They  are  called
70       OFFCORE_RESPONSE_0 and OFFCORE_RESPONSE_1.
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72       Those  events  need special treatment in the performance monitoring in‐
73       frastructure because each event uses an extra register  to  store  some
74       settings.  Thus, in case multiple offcore_response events are monitored
75       simultaneously, the kernel needs to manage the sharing  of  that  extra
76       register.
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78       The  offcore_response  events are exposed as a normal events by the li‐
79       brary. The extra settings are exposed as regular  umasks.  The  library
80       takes  care  of  encoding the events according to the underlying kernel
81       interface.
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83       On Intel Broadwell, the umasks are divided into three  categories:  re‐
84       quest, supplier and snoop. The user must provide at least one umask for
85       each category. The categories are shown in the umask descriptions.
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87       There is also the special response umask called ANY_RESPONSE. When this
88       umask is used then it overrides any supplier and snoop umasks. In other
89       words, users can specify either ANY_RESPONSE  OR  any  combinations  of
90       supplier + snoops.
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92       In  case no supplier or snoop is specified, the library defaults to us‐
93       ing ANY_RESPONSE.
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95       For instance, the following are valid event selections:
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97       OFFCORE_RESPONSE_0:DMND_DATA_RD:ANY_RESPONSE
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99       OFFCORE_RESPONSE_0:ANY_REQUEST
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101       OFFCORE_RESPONSE_0:ANY_RFO:LLC_HITM:SNOOP_ANY
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104       But the following are illegal:
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107       OFFCORE_RESPONSE_0:ANY_RFO:LLC_HITM:ANY_RESPONSE
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109       OFFCORE_RESPONSE_0:ANY_RFO:LLC_HITM:SNOOP_ANY:ANY_RESPONSE
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AUTHORS

113       Stephane Eranian <eranian@gmail.com>
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117                                 October, 2014                       LIBPFM(3)
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