1LIBPFM(3) Linux Programmer's Manual LIBPFM(3)
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6 libpfm_intel_bdx_unc_pcu - support for Intel Broadwell Server Power
7 Controller Unit (PCU) uncore PMU
8
10 #include <perfmon/pfmlib.h>
11 PMU name: bdx_unc_pcu
13 PMU desc: Intel Broadwell Server PCU uncore PMU
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17 The library supports the Intel Broadwell Server Power Controller Unit
18 uncore PMU. This PMU model only exists on various Broadwell server
19 models (79, 86).
20
23 The following modifiers are supported on Intel Broadwell server PCU
24 uncore PMU:
25 e Enable edge detection, i.e., count only when there is a state
27 transition from no occurrence of the event to at least one
28 occurrence. This modifier must be combined with a threshold mod‐
29 ifier (t) with a value greater or equal to one. This is a bool‐
30 ean modifier.
31 t Set the threshold value. When set to a non-zero value, the
33 counter counts the number of HA cycles in which the number of
34 occurrences of the event is greater or equal to the threshold.
35 This is an integer modifier with values in the range [0:15].
36 i Invert the meaning of the threshold or edge filter. If set, the
38 event counts when strictly less than N occurrences occur per
39 cycle if threshold is set to N. When invert is set, then thresh‐
40 old must be set to non-zero value. If set, the event counts when
41 the event transitions from occurring to not occurring (falling
42 edge) when edge detection is set. This is a boolean modifier
43 ff Enable frequency band filtering. This modifier applies only to
45 the UNC_P_FREQ_BANDx_CYCLES events, where x is [0-3]. The modi‐
46 fiers expects an integer in the range [0-255]. The value is
47 interpreted as a frequency value to be multiplied by 100Mhz.
48 Thus if the value is 32, then all cycles where the processor is
49 running at 3.2GHz and more are counted.
50
53 There are 3 events which support frequency band filtering, namely,
54 UNC_P_FREQ_BAND0_CYCLES, UNC_P_FREQ_BAND1_CYCLES,
55 UNC_P_FREQ_BAND2_CYCLES, UNC_P_FREQ_BAND3_CYCLES. The frequency filter
56 (available via the ff modifier) is stored into a PMU shared register
57 which hold all 4 possible frequency bands, one per event. However, the
58 library generate the encoding for each event individually because it
59 processes events one at a time. The caller or the underlying kernel
60 interface may have to merge the band filter settings to program the
61 filter register properly.
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65 Stephane Eranian <eranian@gmail.com>
66 June, 2017 LIBPFM(3)