1 1
2 The contents of this directory allow users to 2 The contents of this directory allow users to specify PMU events in their
3 CPUs by their symbolic names rather than raw e 3 CPUs by their symbolic names rather than raw event codes (see example below).
4 4
5 The main program in this directory, is the 'je 5 The main program in this directory, is the 'jevents', which is built and
6 executed _BEFORE_ the perf binary itself is bu 6 executed _BEFORE_ the perf binary itself is built.
7 7
8 The 'jevents' program tries to locate and proc 8 The 'jevents' program tries to locate and process JSON files in the directory
9 tree tools/perf/pmu-events/arch/foo. 9 tree tools/perf/pmu-events/arch/foo.
10 10
11 - Regular files with '.json' extension 11 - Regular files with '.json' extension in the name are assumed to be
12 JSON files, each of which describes 12 JSON files, each of which describes a set of PMU events.
13 13
14 - The CSV file that maps a specific CP !! 14 - Regular files with basename starting with 'mapfile.csv' are assumed
15 be named 'mapfile.csv' (see below fo !! 15 to be a CSV file that maps a specific CPU to its set of PMU events.
>> 16 (see below for mapfile format)
16 17
17 - Directories are traversed, but all o 18 - Directories are traversed, but all other files are ignored.
18 19
19 - To reduce JSON event duplication per <<
20 use "ArchStdEvent" keyword to derefe <<
21 events", defined in architecture sta <<
22 Architecture standard JSONs must be <<
23 folder. Matching is based on the "Ev <<
24 <<
25 The PMU events supported by a CPU model are ex 20 The PMU events supported by a CPU model are expected to grouped into topics
26 such as Pipelining, Cache, Memory, Floating-po 21 such as Pipelining, Cache, Memory, Floating-point etc. All events for a topic
27 should be placed in a separate JSON file - whe 22 should be placed in a separate JSON file - where the file name identifies
28 the topic. Eg: "Floating-point.json". 23 the topic. Eg: "Floating-point.json".
29 24
30 All the topic JSON files for a CPU model/famil 25 All the topic JSON files for a CPU model/family should be in a separate
31 sub directory. Thus for the Silvermont X86 CPU 26 sub directory. Thus for the Silvermont X86 CPU:
32 27
33 $ ls tools/perf/pmu-events/arch/x86/si !! 28 $ ls tools/perf/pmu-events/arch/x86/Silvermont_core
34 cache.json memory.json virtual- !! 29 Cache.json Memory.json Virtual-Memory.json
35 frontend.json pipeline.json !! 30 Frontend.json Pipeline.json
36 <<
37 The JSONs folder for a CPU model/family may be <<
38 folder, or may be placed in a vendor sub-folde <<
39 for instances where the arch and vendor are no <<
40 31
41 Using the JSON files and the mapfile, 'jevents 32 Using the JSON files and the mapfile, 'jevents' generates the C source file,
42 'pmu-events.c', which encodes the two sets of 33 'pmu-events.c', which encodes the two sets of tables:
43 34
44 - Set of 'PMU events tables' for all k 35 - Set of 'PMU events tables' for all known CPUs in the architecture,
45 (one table like the following, per J 36 (one table like the following, per JSON file; table name 'pme_power8'
46 is derived from JSON file name, 'pow 37 is derived from JSON file name, 'power8.json').
47 38
48 struct pmu_event pme_power8[] 39 struct pmu_event pme_power8[] = {
49 40
50 ... 41 ...
51 42
52 { 43 {
53 .name = "pm_1p 44 .name = "pm_1plus_ppc_cmpl",
54 .event = "even 45 .event = "event=0x100f2",
55 .desc = "1 or 46 .desc = "1 or more ppc insts finished,",
56 }, 47 },
57 48
58 ... 49 ...
59 } 50 }
60 51
61 - A 'mapping table' that maps each CPU 52 - A 'mapping table' that maps each CPU of the architecture, to its
62 'PMU events table' 53 'PMU events table'
63 54
64 struct pmu_events_map pmu_even 55 struct pmu_events_map pmu_events_map[] = {
65 { 56 {
66 .cpuid = "004b0000", 57 .cpuid = "004b0000",
67 .version = "1", 58 .version = "1",
68 .type = "core", 59 .type = "core",
69 .table = pme_power8 60 .table = pme_power8
70 }, 61 },
71 ... 62 ...
72 63
73 }; 64 };
74 65
75 After the 'pmu-events.c' is generated, it is c 66 After the 'pmu-events.c' is generated, it is compiled and the resulting
76 'pmu-events.o' is added to 'libperf.a' which i 67 'pmu-events.o' is added to 'libperf.a' which is then used to build perf.
77 68
78 NOTES: 69 NOTES:
79 1. Several CPUs can support same set o 70 1. Several CPUs can support same set of events and hence use a common
80 JSON file. Hence several entries in 71 JSON file. Hence several entries in the pmu_events_map[] could map
81 to a single 'PMU events table'. 72 to a single 'PMU events table'.
82 73
83 2. The 'pmu-events.h' has an extern de 74 2. The 'pmu-events.h' has an extern declaration for the mapping table
84 and the generated 'pmu-events.c' de 75 and the generated 'pmu-events.c' defines this table.
85 76
86 3. _All_ known CPU tables for architec 77 3. _All_ known CPU tables for architecture are included in the perf
87 binary. 78 binary.
88 79
89 At run time, perf determines the actual CPU it 80 At run time, perf determines the actual CPU it is running on, finds the
90 matching events table and builds aliases for t 81 matching events table and builds aliases for those events. This allows
91 users to specify events by their name: 82 users to specify events by their name:
92 83
93 $ perf stat -e pm_1plus_ppc_cmpl sleep 84 $ perf stat -e pm_1plus_ppc_cmpl sleep 1
94 85
95 where 'pm_1plus_ppc_cmpl' is a Power8 PMU even 86 where 'pm_1plus_ppc_cmpl' is a Power8 PMU event.
96 87
97 However some errors in processing may cause th !! 88 However some errors in processing may cause the perf build to fail.
98 89
99 Mapfile format 90 Mapfile format
100 =============== 91 ===============
101 92
102 The mapfile enables multiple CPU models to sha 93 The mapfile enables multiple CPU models to share a single set of PMU events.
103 It is required even if such mapping is 1:1. 94 It is required even if such mapping is 1:1.
104 95
105 The mapfile.csv format is expected to be: 96 The mapfile.csv format is expected to be:
106 97
107 Header line 98 Header line
108 CPUID,Version,Dir/path/name,Type 99 CPUID,Version,Dir/path/name,Type
109 100
110 where: 101 where:
111 102
112 Comma: 103 Comma:
113 is the required field delimite 104 is the required field delimiter (i.e other fields cannot
114 have commas within them). 105 have commas within them).
115 106
116 Comments: 107 Comments:
117 Lines in which the first chara 108 Lines in which the first character is either '\n' or '#'
118 are ignored. 109 are ignored.
119 110
120 Header line 111 Header line
121 The header line is the first l 112 The header line is the first line in the file, which is
122 always _IGNORED_. It can be em !! 113 always _IGNORED_. It can empty.
123 114
124 CPUID: 115 CPUID:
125 CPUID is an arch-specific char 116 CPUID is an arch-specific char string, that can be used
126 to identify CPU (and associate 117 to identify CPU (and associate it with a set of PMU events
127 it supports). Multiple CPUIDS 118 it supports). Multiple CPUIDS can point to the same
128 File/path/name.json. 119 File/path/name.json.
129 120
130 Example: 121 Example:
131 CPUID == 'GenuineIntel 122 CPUID == 'GenuineIntel-6-2E' (on x86).
132 CPUID == '004b0100' (P 123 CPUID == '004b0100' (PVR value in Powerpc)
133 Version: 124 Version:
134 is the Version of the mapfile. 125 is the Version of the mapfile.
135 126
136 Dir/path/name: 127 Dir/path/name:
137 is the pathname to the directo 128 is the pathname to the directory containing the CPU's JSON
138 files, relative to the directo 129 files, relative to the directory containing the mapfile.csv
139 130
140 Type: 131 Type:
141 indicates whether the events a !! 132 indicates whether the events or "core" or "uncore" events.
142 133
143 134
144 Eg: 135 Eg:
145 136
146 $ grep silvermont tools/perf/pmu-event !! 137 $ grep Silvermont tools/perf/pmu-events/arch/x86/mapfile.csv
147 GenuineIntel-6-37,v13,silvermont,core !! 138 GenuineIntel-6-37,V13,Silvermont_core,core
148 GenuineIntel-6-4D,v13,silvermont,core !! 139 GenuineIntel-6-4D,V13,Silvermont_core,core
149 GenuineIntel-6-4C,v13,silvermont,core !! 140 GenuineIntel-6-4C,V13,Silvermont_core,core
150 141
151 i.e the three CPU models use the JSON 142 i.e the three CPU models use the JSON files (i.e PMU events) listed
152 in the directory 'tools/perf/pmu-event !! 143 in the directory 'tools/perf/pmu-events/arch/x86/Silvermont_core'.
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