OpenCloudOS-Kernel/tools/perf/Documentation/perf-top.txt

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perf-top(1)
===========
NAME
----
perf-top - System profiling tool.
SYNOPSIS
--------
[verse]
'perf top' [-e <EVENT> | --event=EVENT] [<options>]
DESCRIPTION
-----------
This command generates and displays a performance counter profile in real time.
OPTIONS
-------
-a::
--all-cpus::
System-wide collection. (default)
-c <count>::
--count=<count>::
Event period to sample.
-C <cpu-list>::
--cpu=<cpu>::
Monitor only on the list of CPUs provided. Multiple CPUs can be provided as a
comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
Default is to monitor all CPUS.
-d <seconds>::
--delay=<seconds>::
Number of seconds to delay between refreshes.
-e <event>::
--event=<event>::
Select the PMU event. Selection can be a symbolic event name
(use 'perf list' to list all events) or a raw PMU
event (eventsel+umask) in the form of rNNN where NNN is a
hexadecimal event descriptor.
-E <entries>::
--entries=<entries>::
Display this many functions.
-f <count>::
--count-filter=<count>::
Only display functions with more events than this.
--group::
Put the counters into a counter group.
-F <freq>::
--freq=<freq>::
Profile at this frequency.
-i::
--inherit::
Child tasks do not inherit counters.
-k <path>::
--vmlinux=<path>::
Path to vmlinux. Required for annotation functionality.
-m <pages>::
--mmap-pages=<pages>::
Number of mmap data pages (must be a power of two) or size
specification with appended unit character - B/K/M/G. The
size is rounded up to have nearest pages power of two value.
-p <pid>::
--pid=<pid>::
Profile events on existing Process ID (comma separated list).
-t <tid>::
--tid=<tid>::
Profile events on existing thread ID (comma separated list).
-u::
--uid=::
Record events in threads owned by uid. Name or number.
-r <priority>::
--realtime=<priority>::
Collect data with this RT SCHED_FIFO priority.
--sym-annotate=<symbol>::
Annotate this symbol.
-K::
--hide_kernel_symbols::
Hide kernel symbols.
-U::
--hide_user_symbols::
Hide user symbols.
--demangle-kernel::
Demangle kernel symbols.
-D::
--dump-symtab::
Dump the symbol table used for profiling.
-v::
--verbose::
Be more verbose (show counter open errors, etc).
-z::
--zero::
Zero history across display updates.
-s::
--sort::
Sort by key(s): pid, comm, dso, symbol, parent, srcline, weight,
local_weight, abort, in_tx, transaction, overhead, sample, period.
Please see description of --sort in the perf-report man page.
--fields=::
Specify output field - multiple keys can be specified in CSV format.
Following fields are available:
overhead, overhead_sys, overhead_us, overhead_children, sample and period.
Also it can contain any sort key(s).
By default, every sort keys not specified in --field will be appended
automatically.
-n::
--show-nr-samples::
Show a column with the number of samples.
--show-total-period::
Show a column with the sum of periods.
--dsos::
Only consider symbols in these dsos. This option will affect the
percentage of the overhead column. See --percentage for more info.
--comms::
Only consider symbols in these comms. This option will affect the
percentage of the overhead column. See --percentage for more info.
--symbols::
Only consider these symbols. This option will affect the
percentage of the overhead column. See --percentage for more info.
-M::
--disassembler-style=:: Set disassembler style for objdump.
--source::
Interleave source code with assembly code. Enabled by default,
disable with --no-source.
--asm-raw::
Show raw instruction encoding of assembly instructions.
-g::
Enables call-graph (stack chain/backtrace) recording.
--call-graph::
Setup and enable call-graph (stack chain/backtrace) recording,
implies -g.
--children::
Accumulate callchain of children to parent entry so that then can
show up in the output. The output will have a new "Children" column
and will be sorted on the data. It requires -g/--call-graph option
enabled.
--max-stack::
Set the stack depth limit when parsing the callchain, anything
beyond the specified depth will be ignored. This is a trade-off
between information loss and faster processing especially for
workloads that can have a very long callchain stack.
Default: 127
--ignore-callees=<regex>::
Ignore callees of the function(s) matching the given regex.
This has the effect of collecting the callers of each such
function into one place in the call-graph tree.
--percent-limit::
Do not show entries which have an overhead under that percent.
(Default: 0).
--percentage::
Determine how to display the overhead percentage of filtered entries.
Filters can be applied by --comms, --dsos and/or --symbols options and
Zoom operations on the TUI (thread, dso, etc).
"relative" means it's relative to filtered entries only so that the
sum of shown entries will be always 100%. "absolute" means it retains
the original value before and after the filter is applied.
-w::
--column-widths=<width[,width...]>::
Force each column width to the provided list, for large terminal
readability. 0 means no limit (default behavior).
INTERACTIVE PROMPTING KEYS
--------------------------
[d]::
Display refresh delay.
[e]::
Number of entries to display.
[E]::
Event to display when multiple counters are active.
[f]::
Profile display filter (>= hit count).
[F]::
Annotation display filter (>= % of total).
[s]::
Annotate symbol.
[S]::
Stop annotation, return to full profile display.
[z]::
Toggle event count zeroing across display updates.
[qQ]::
Quit.
Pressing any unmapped key displays a menu, and prompts for input.
SEE ALSO
--------
linkperf:perf-stat[1], linkperf:perf-list[1], linkperf:perf-report[1]