SYNOPSIS

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.

-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.

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.