xref: /linux/tools/perf/Documentation/perf-top.txt (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
1perf-top(1)
2===========
3
4NAME
5----
6perf-top - System profiling tool.
7
8SYNOPSIS
9--------
10[verse]
11'perf top' [-e <EVENT> | --event=EVENT] [<options>]
12
13DESCRIPTION
14-----------
15This command generates and displays a performance counter profile in real time.
16
17
18OPTIONS
19-------
20-a::
21--all-cpus::
22        System-wide collection.  (default)
23
24-c <count>::
25--count=<count>::
26	Event period to sample.
27
28-C <cpu-list>::
29--cpu=<cpu>::
30Monitor only on the list of CPUs provided. Multiple CPUs can be provided as a
31comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
32Default is to monitor all CPUS.
33
34-d <seconds>::
35--delay=<seconds>::
36	Number of seconds to delay between refreshes.
37
38-e <event>::
39--event=<event>::
40	Select the PMU event. Selection can be a symbolic event name
41	(use 'perf list' to list all events) or a raw PMU
42	event (eventsel+umask) in the form of rNNN where NNN is a
43	hexadecimal event descriptor.
44
45-E <entries>::
46--entries=<entries>::
47	Display this many functions.
48
49-f <count>::
50--count-filter=<count>::
51	Only display functions with more events than this.
52
53--group::
54        Put the counters into a counter group.
55
56-F <freq>::
57--freq=<freq>::
58	Profile at this frequency.
59
60-i::
61--inherit::
62	Child tasks do not inherit counters.
63
64-k <path>::
65--vmlinux=<path>::
66	Path to vmlinux.  Required for annotation functionality.
67
68-m <pages>::
69--mmap-pages=<pages>::
70	Number of mmap data pages (must be a power of two) or size
71	specification with appended unit character - B/K/M/G. The
72	size is rounded up to have nearest pages power of two value.
73
74-p <pid>::
75--pid=<pid>::
76	Profile events on existing Process ID (comma separated list).
77
78-t <tid>::
79--tid=<tid>::
80        Profile events on existing thread ID (comma separated list).
81
82-u::
83--uid=::
84        Record events in threads owned by uid. Name or number.
85
86-r <priority>::
87--realtime=<priority>::
88	Collect data with this RT SCHED_FIFO priority.
89
90--sym-annotate=<symbol>::
91        Annotate this symbol.
92
93-K::
94--hide_kernel_symbols::
95        Hide kernel symbols.
96
97-U::
98--hide_user_symbols::
99        Hide user symbols.
100
101-D::
102--dump-symtab::
103        Dump the symbol table used for profiling.
104
105-v::
106--verbose::
107	Be more verbose (show counter open errors, etc).
108
109-z::
110--zero::
111	Zero history across display updates.
112
113-s::
114--sort::
115	Sort by key(s): pid, comm, dso, symbol, parent, srcline, weight,
116	local_weight, abort, in_tx, transaction, overhead, sample, period.
117	Please see description of --sort in the perf-report man page.
118
119--fields=::
120	Specify output field - multiple keys can be specified in CSV format.
121	Following fields are available:
122	overhead, overhead_sys, overhead_us, overhead_children, sample and period.
123	Also it can contain any sort key(s).
124
125	By default, every sort keys not specified in --field will be appended
126	automatically.
127
128-n::
129--show-nr-samples::
130	Show a column with the number of samples.
131
132--show-total-period::
133	Show a column with the sum of periods.
134
135--dsos::
136	Only consider symbols in these dsos.  This option will affect the
137	percentage of the overhead column.  See --percentage for more info.
138
139--comms::
140	Only consider symbols in these comms.  This option will affect the
141	percentage of the overhead column.  See --percentage for more info.
142
143--symbols::
144	Only consider these symbols.  This option will affect the
145	percentage of the overhead column.  See --percentage for more info.
146
147-M::
148--disassembler-style=:: Set disassembler style for objdump.
149
150--source::
151	Interleave source code with assembly code. Enabled by default,
152	disable with --no-source.
153
154--asm-raw::
155	Show raw instruction encoding of assembly instructions.
156
157-g::
158	Enables call-graph (stack chain/backtrace) recording.
159
160--call-graph::
161	Setup and enable call-graph (stack chain/backtrace) recording,
162	implies -g.
163
164--children::
165	Accumulate callchain of children to parent entry so that then can
166	show up in the output.  The output will have a new "Children" column
167	and will be sorted on the data.  It requires -g/--call-graph option
168	enabled.
169
170--max-stack::
171	Set the stack depth limit when parsing the callchain, anything
172	beyond the specified depth will be ignored. This is a trade-off
173	between information loss and faster processing especially for
174	workloads that can have a very long callchain stack.
175
176	Default: 127
177
178--ignore-callees=<regex>::
179        Ignore callees of the function(s) matching the given regex.
180        This has the effect of collecting the callers of each such
181        function into one place in the call-graph tree.
182
183--percent-limit::
184	Do not show entries which have an overhead under that percent.
185	(Default: 0).
186
187--percentage::
188	Determine how to display the overhead percentage of filtered entries.
189	Filters can be applied by --comms, --dsos and/or --symbols options and
190	Zoom operations on the TUI (thread, dso, etc).
191
192	"relative" means it's relative to filtered entries only so that the
193	sum of shown entries will be always 100%. "absolute" means it retains
194	the original value before and after the filter is applied.
195
196INTERACTIVE PROMPTING KEYS
197--------------------------
198
199[d]::
200	Display refresh delay.
201
202[e]::
203	Number of entries to display.
204
205[E]::
206	Event to display when multiple counters are active.
207
208[f]::
209	Profile display filter (>= hit count).
210
211[F]::
212	Annotation display filter (>= % of total).
213
214[s]::
215	Annotate symbol.
216
217[S]::
218	Stop annotation, return to full profile display.
219
220[z]::
221	Toggle event count zeroing across display updates.
222
223[qQ]::
224	Quit.
225
226Pressing any unmapped key displays a menu, and prompts for input.
227
228
229SEE ALSO
230--------
231linkperf:perf-stat[1], linkperf:perf-list[1], linkperf:perf-report[1]
232