--- name: "perf_3.16-top" section: "1" platform: "linux" package: "linux-tools-3.16" version: "3.16.56-1" release: "Debian 8 (Jessie)" platforms: ["linux"] url: "https://new.carta.tech/perf_3.16-top" --- # perf\_3.16-top(1) System profiling tool. ## NAME perf-top - System profiling tool. ## SYNOPSIS ``` perf top [-e | --event=EVENT] [] ``` ## DESCRIPTION This command generates and displays a performance counter profile in real time. ## OPTIONS - \-a, --all-cpus System-wide collection. (default) - \-c \, --count=\ Event period to sample. - \-C \, --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 \, --delay=\ Number of seconds to delay between refreshes. - \-e \, --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=\ Display this many functions. - \-f \, --count-filter=\ Only display functions with more events than this. - \--group Put the counters into a counter group. - \-F \, --freq=\ Profile at this frequency. - \-i, --inherit Child tasks do not inherit counters. - \-k \, --vmlinux=\ Path to vmlinux. Required for annotation functionality. - \-m \, --mmap-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=\ Profile events on existing Process ID (comma separated list). - \-t \, --tid=\ Profile events on existing thread ID (comma separated list). \-u, --uid= Record events in threads owned by uid. Name or number. - \-r \, --realtime=\ Collect data with this RT SCHED\_FIFO priority. - \--sym-annotate=\ 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=\ 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. ## SEE ALSO [**perf\_3.16-stat**(1)](/perf_3.16-stat/1.md), [**perf\_3.16-list**(1)](/perf_3.16-list/1.md), [**perf\_3.16-report**(1)](/perf_3.16-report/1.md)