perf-top (1) Linux Manual Page
perf-top – System profiling tool.
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.
–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.