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

6       libpfm_intel_ivb - support for Intel Ivy Bridge core PMU
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SYNOPSIS

9       #include <perfmon/pfmlib.h>
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11       PMU name: ivb
12       PMU desc: Intel Ivy Bridge
13       PMU name: ivb_ep
14       PMU desc: Intel Ivy Bridge EP
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DESCRIPTION

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

30       The following modifiers are supported on Intel Ivy Bridge processors:
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32       u      Measure  at  user level which includes privilege levels 1, 2, 3.
33              This corresponds to PFM_PLM3.  This is a boolean modifier.
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35       k      Measure at kernel level which includes privilege level  0.  This
36              corresponds to PFM_PLM0.  This is a boolean modifier.
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38       i      Invert  the  meaning  of  the  event. The counter will now count
39              cycles in which the event is not occurring. This  is  a  boolean
40              modifier
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42       e      Enable  edge  detection,  i.e., count only when there is a state
43              transition from no occurrence of  the  event  to  at  least  one
44              occurrence.  This  modifier must be combined with a counter mask
45              modifier (m) with a value greater or equal to one.   This  is  a
46              boolean modifier.
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48       c      Set  the  counter  mask value. The mask acts as a threshold. The
49              counter will count the number of cycles in which the  number  of
50              occurrences  of  the event is greater or equal to the threshold.
51              This is an integer modifier with values in the range [0:255].
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53       t      Measure on both threads at the same time assuming  hyper-thread‐
54              ing is enabled. This is a boolean modifier.
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56       ldlat  Pass        a        latency        threshold       to       the
57              MEM_TRANS_RETIRED:LATENCY_ABOVE_THRESHOLD  event.   This  is  an
58              integer  attribute  that  must  be in the range [3:65535]. It is
59              required for this event.  Note that the event must be used  with
60              precise sampling (PEBS).
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OFFCORE_RESPONSE events

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

108       Stephane Eranian <eranian@gmail.com>
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112                                 August, 2012                        LIBPFM(3)
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