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

6       libpfm_intel_nhm - support for Intel Nehalem core PMU
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SYNOPSIS

9       #include <perfmon/pfmlib.h>
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11       PMU name: nhm
12       PMU desc: Intel Nehalem
13       PMU name: nhm_ex
14       PMU desc: Intel Nehalem EX
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DESCRIPTION

18       The  library  supports  the  Intel Nehalem core PMU. It should be noted
19       that this PMU model only covers the each core's PMU and not the  socket
20       level PMU. It is provided separately. Support is provided for the Intel
21       Core i7 and Core i5 processors.
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MODIFIERS

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

59       The library is able to encode the OFFCORE_RESPONSE_0 event. This  is  a
60       special  event  because  it needs a second MSR (0x1a6) to be programmed
61       for the event to count properly. Thus two  values  are  necessary.  The
62       first  value can be programmed on any of the generic counters. The sec‐
63       ond value goes into the dedicated MSR (0x1a6).
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65       The OFFCORE_RESPONSE event is exposed as a normal  event  with  several
66       umasks  which are divided in two groups: request and response. The user
67       must provide at least one umask from each group.   For  instance,  OFF‐
68       CORE_RESPONSE_0:ANY_DATA:LOCAL_DRAM.
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70       When  using  pfm_get_event_encoding(),  two 64-bit values are returned.
71       The first value corresponds to what needs to be programmed into any  of
72       the generic counters. The second value must be programmed into the ded‐
73       icated MSR (0x1a6).
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75       When using an OS-specific  encoding  routine,  the  way  the  event  is
76       encoded  is  OS  specific. Refer to the corresponding man page for more
77       information.
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AUTHORS

81       Stephane Eranian <eranian@gmail.com>
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85                                September, 2009                      LIBPFM(3)