1PERF-LIST(1)                      perf Manual                     PERF-LIST(1)
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NAME

6       perf-list - List all symbolic event types
7

SYNOPSIS

9       perf list [--no-desc] [--long-desc]
10                   [hw|sw|cache|tracepoint|pmu|sdt|metric|metricgroup|event_glob]
11

DESCRIPTION

13       This command displays the symbolic event types which can be selected in
14       the various perf commands with the -e option.
15

OPTIONS

17       -d, --desc
18           Print extra event descriptions. (default)
19
20       --no-desc
21           Don’t print descriptions.
22
23       -v, --long-desc
24           Print longer event descriptions.
25
26       --debug
27           Enable debugging output.
28
29       --details
30           Print how named events are resolved internally into perf events,
31           and also any extra expressions computed by perf stat.
32
33       --deprecated
34           Print deprecated events. By default the deprecated events are
35           hidden.
36
37       --cputype
38           Print events applying cpu with this type for hybrid platform (e.g.
39           --cputype core or --cputype atom)
40

EVENT MODIFIERS

42       Events can optionally have a modifier by appending a colon and one or
43       more modifiers. Modifiers allow the user to restrict the events to be
44       counted. The following modifiers exist:
45
46           u - user-space counting
47           k - kernel counting
48           h - hypervisor counting
49           I - non idle counting
50           G - guest counting (in KVM guests)
51           H - host counting (not in KVM guests)
52           p - precise level
53           P - use maximum detected precise level
54           S - read sample value (PERF_SAMPLE_READ)
55           D - pin the event to the PMU
56           W - group is weak and will fallback to non-group if not schedulable,
57           e - group or event are exclusive and do not share the PMU
58
59       The p modifier can be used for specifying how precise the instruction
60       address should be. The p modifier can be specified multiple times:
61
62           0 - SAMPLE_IP can have arbitrary skid
63           1 - SAMPLE_IP must have constant skid
64           2 - SAMPLE_IP requested to have 0 skid
65           3 - SAMPLE_IP must have 0 skid, or uses randomization to avoid
66               sample shadowing effects.
67
68       For Intel systems precise event sampling is implemented with PEBS which
69       supports up to precise-level 2, and precise level 3 for some special
70       cases
71
72       On AMD systems it is implemented using IBS (up to precise-level 2). The
73       precise modifier works with event types 0x76 (cpu-cycles, CPU clocks
74       not halted) and 0xC1 (micro-ops retired). Both events map to IBS
75       execution sampling (IBS op) with the IBS Op Counter Control bit
76       (IbsOpCntCtl) set respectively (see the Core Complex (CCX) → Processor
77       x86 Core → Instruction Based Sampling (IBS) section of the [AMD
78       Processor Programming Reference (PPR)] relevant to the family, model
79       and stepping of the processor being used).
80
81       Manual Volume 2: System Programming, 13.3 Instruction-Based Sampling).
82       Examples to use IBS:
83
84           perf record -a -e cpu-cycles:p ...    # use ibs op counting cycles
85           perf record -a -e r076:p ...          # same as -e cpu-cycles:p
86           perf record -a -e r0C1:p ...          # use ibs op counting micro-ops
87

RAW HARDWARE EVENT DESCRIPTOR

89       Even when an event is not available in a symbolic form within perf
90       right now, it can be encoded in a per processor specific way.
91
92       For instance on x86 CPUs, N is a hexadecimal value that represents the
93       raw register encoding with the layout of IA32_PERFEVTSELx MSRs (see
94       [Intel® 64 and IA-32 Architectures Software Developer’s Manual Volume
95       3B: System Programming Guide] Figure 30-1 Layout of IA32_PERFEVTSELx
96       MSRs) or AMD’s PERF_CTL MSRs (see the Core Complex (CCX) → Processor
97       x86 Core → MSR Registers section of the [AMD Processor Programming
98       Reference (PPR)] relevant to the family, model and stepping of the
99       processor being used).
100
101       Note: Only the following bit fields can be set in x86 counter
102       registers: event, umask, edge, inv, cmask. Esp. guest/host only and
103       OS/user mode flags must be setup using EVENT MODIFIERS.
104
105       Example:
106
107       If the Intel docs for a QM720 Core i7 describe an event as:
108
109           Event  Umask  Event Mask
110           Num.   Value  Mnemonic    Description                        Comment
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112           A8H      01H  LSD.UOPS    Counts the number of micro-ops     Use cmask=1 and
113                                     delivered by loop stream detector  invert to count
114                                                                        cycles
115
116       raw encoding of 0x1A8 can be used:
117
118           perf stat -e r1a8 -a sleep 1
119           perf record -e r1a8 ...
120
121       It’s also possible to use pmu syntax:
122
123           perf record -e r1a8 -a sleep 1
124           perf record -e cpu/r1a8/ ...
125           perf record -e cpu/r0x1a8/ ...
126
127       Some processors, like those from AMD, support event codes and unit
128       masks larger than a byte. In such cases, the bits corresponding to the
129       event configuration parameters can be seen with:
130
131           cat /sys/bus/event_source/devices/<pmu>/format/<config>
132
133       Example:
134
135       If the AMD docs for an EPYC 7713 processor describe an event as:
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137           Event  Umask  Event Mask
138           Num.   Value  Mnemonic                        Description
139
140           28FH     03H  op_cache_hit_miss.op_cache_hit  Counts Op Cache micro-tag
141                                                         hit events.
142
143       raw encoding of 0x0328F cannot be used since the upper nibble of the
144       EventSelect bits have to be specified via bits 32-35 as can be seen
145       with:
146
147           cat /sys/bus/event_source/devices/cpu/format/event
148
149       raw encoding of 0x20000038F should be used instead:
150
151           perf stat -e r20000038f -a sleep 1
152           perf record -e r20000038f ...
153
154       It’s also possible to use pmu syntax:
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156           perf record -e r20000038f -a sleep 1
157           perf record -e cpu/r20000038f/ ...
158           perf record -e cpu/r0x20000038f/ ...
159
160       You should refer to the processor specific documentation for getting
161       these details. Some of them are referenced in the SEE ALSO section
162       below.
163

ARBITRARY PMUS

165       perf also supports an extended syntax for specifying raw parameters to
166       PMUs. Using this typically requires looking up the specific event in
167       the CPU vendor specific documentation.
168
169       The available PMUs and their raw parameters can be listed with
170
171           ls /sys/devices/*/format
172
173       For example the raw event "LSD.UOPS" core pmu event above could be
174       specified as
175
176           perf stat -e cpu/event=0xa8,umask=0x1,name=LSD.UOPS_CYCLES,cmask=0x1/ ...
177
178           or using extended name syntax
179
180           perf stat -e cpu/event=0xa8,umask=0x1,cmask=0x1,name=\'LSD.UOPS_CYCLES:cmask=0x1\'/ ...
181

PER SOCKET PMUS

183       Some PMUs are not associated with a core, but with a whole CPU socket.
184       Events on these PMUs generally cannot be sampled, but only counted
185       globally with perf stat -a. They can be bound to one logical CPU, but
186       will measure all the CPUs in the same socket.
187
188       This example measures memory bandwidth every second on the first memory
189       controller on socket 0 of a Intel Xeon system
190
191           perf stat -C 0 -a uncore_imc_0/cas_count_read/,uncore_imc_0/cas_count_write/ -I 1000 ...
192
193       Each memory controller has its own PMU. Measuring the complete system
194       bandwidth would require specifying all imc PMUs (see perf list output),
195       and adding the values together. To simplify creation of multiple
196       events, prefix and glob matching is supported in the PMU name, and the
197       prefix uncore_ is also ignored when performing the match. So the
198       command above can be expanded to all memory controllers by using the
199       syntaxes:
200
201           perf stat -C 0 -a imc/cas_count_read/,imc/cas_count_write/ -I 1000 ...
202           perf stat -C 0 -a *imc*/cas_count_read/,*imc*/cas_count_write/ -I 1000 ...
203
204       This example measures the combined core power every second
205
206           perf stat -I 1000 -e power/energy-cores/  -a
207

ACCESS RESTRICTIONS

209       For non root users generally only context switched PMU events are
210       available. This is normally only the events in the cpu PMU, the
211       predefined events like cycles and instructions and some software
212       events.
213
214       Other PMUs and global measurements are normally root only. Some event
215       qualifiers, such as "any", are also root only.
216
217       This can be overridden by setting the kernel.perf_event_paranoid sysctl
218       to -1, which allows non root to use these events.
219
220       For accessing trace point events perf needs to have read access to
221       /sys/kernel/debug/tracing, even when perf_event_paranoid is in a
222       relaxed setting.
223

TRACING

225       Some PMUs control advanced hardware tracing capabilities, such as Intel
226       PT, that allows low overhead execution tracing. These are described in
227       a separate intel-pt.txt document.
228

PARAMETERIZED EVENTS

230       Some pmu events listed by perf-list will be displayed with ? in them.
231       For example:
232
233           hv_gpci/dtbp_ptitc,phys_processor_idx=?/
234
235       This means that when provided as an event, a value for ? must also be
236       supplied. For example:
237
238           perf stat -C 0 -e 'hv_gpci/dtbp_ptitc,phys_processor_idx=0x2/' ...
239
240       EVENT QUALIFIERS:
241
242       It is also possible to add extra qualifiers to an event:
243
244       percore:
245
246       Sums up the event counts for all hardware threads in a core, e.g.:
247
248           perf stat -e cpu/event=0,umask=0x3,percore=1/
249

EVENT GROUPS

251       Perf supports time based multiplexing of events, when the number of
252       events active exceeds the number of hardware performance counters.
253       Multiplexing can cause measurement errors when the workload changes its
254       execution profile.
255
256       When metrics are computed using formulas from event counts, it is
257       useful to ensure some events are always measured together as a group to
258       minimize multiplexing errors. Event groups can be specified using { }.
259
260           perf stat -e '{instructions,cycles}' ...
261
262       The number of available performance counters depend on the CPU. A group
263       cannot contain more events than available counters. For example Intel
264       Core CPUs typically have four generic performance counters for the
265       core, plus three fixed counters for instructions, cycles and
266       ref-cycles. Some special events have restrictions on which counter they
267       can schedule, and may not support multiple instances in a single group.
268       When too many events are specified in the group some of them will not
269       be measured.
270
271       Globally pinned events can limit the number of counters available for
272       other groups. On x86 systems, the NMI watchdog pins a counter by
273       default. The nmi watchdog can be disabled as root with
274
275           echo 0 > /proc/sys/kernel/nmi_watchdog
276
277       Events from multiple different PMUs cannot be mixed in a group, with
278       some exceptions for software events.
279

LEADER SAMPLING

281       perf also supports group leader sampling using the :S specifier.
282
283           perf record -e '{cycles,instructions}:S' ...
284           perf report --group
285
286       Normally all events in an event group sample, but with :S only the
287       first event (the leader) samples, and it only reads the values of the
288       other events in the group.
289
290       However, in the case AUX area events (e.g. Intel PT or CoreSight), the
291       AUX area event must be the leader, so then the second event samples,
292       not the first.
293

OPTIONS

295       Without options all known events will be listed.
296
297       To limit the list use:
298
299        1. hw or hardware to list hardware events such as cache-misses, etc.
300
301        2. sw or software to list software events such as context switches,
302           etc.
303
304        3. cache or hwcache to list hardware cache events such as
305           L1-dcache-loads, etc.
306
307        4. tracepoint to list all tracepoint events, alternatively use
308           subsys_glob:event_glob to filter by tracepoint subsystems such as
309           sched, block, etc.
310
311        5. pmu to print the kernel supplied PMU events.
312
313        6. sdt to list all Statically Defined Tracepoint events.
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315        7. metric to list metrics
316
317        8. metricgroup to list metricgroups with metrics.
318
319        9. If none of the above is matched, it will apply the supplied glob to
320           all events, printing the ones that match.
321
322       10. As a last resort, it will do a substring search in all event names.
323
324       One or more types can be used at the same time, listing the events for
325       the types specified.
326
327       Support raw format:
328
329        1. --raw-dump, shows the raw-dump of all the events.
330
331        2. --raw-dump [hw|sw|cache|tracepoint|pmu|event_glob], shows the
332           raw-dump of a certain kind of events.
333

SEE ALSO

335       perf-stat(1), perf-top(1), perf-record(1), Intel® 64 and IA-32
336       Architectures Software Developer’s Manual Volume 3B: System Programming
337       Guide[1], AMD Processor Programming Reference (PPR)[2]
338

NOTES

340        1. Intel® 64 and IA-32 Architectures Software Developer’s Manual
341           Volume 3B: System Programming Guide
342           http://www.intel.com/sdm/
343
344        2. AMD Processor Programming Reference (PPR)
345           https://bugzilla.kernel.org/show_bug.cgi?id=206537
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349perf                              06/14/2022                      PERF-LIST(1)
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