[ man7.org ](../../../index.html) > Linux > [ man-pages ](../index.html) |  [ Linux/UNIX system programming training ](http://man7.org/training/)  
---|---  
  
* * *

#  perf-top(1) — Linux manual page

NAME  |  SYNOPSIS  |  DESCRIPTION  |  OPTIONS  |  INTERACTIVE PROMPTING KEYS  |  OVERHEAD CALCULATION  |  SEE ALSO  |  COLOPHON   
---  
|  
      
    
    _PERF-TOP_(1)                    perf Manual                   _PERF-TOP_(1)
    

##  NAME  top

    
    
           perf-top - System profiling tool.
    

##  SYNOPSIS  top

    
    
           _perf top_ [-e <EVENT> | --event=EVENT] [<options>]
    

##  DESCRIPTION  top

    
    
           This command generates and displays a performance counter profile
           in real time.
    

##  OPTIONS  top

    
    
           -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 in the
               form of rN where N is a hexadecimal value that represents the
               raw register encoding with the layout of the event control
               registers as described by entries in
               /sys/bus/event_source/devices/cpu/format/*.
    
           -E <entries>, --entries=<entries>
               Display this many functions.
    
           -f <count>, --count-filter=<count>
               Only display functions with more events than this.
    
           --group-sort-idx
               Sort the output by the event at the index n in group. If n is
               invalid, sort by the first event. It can support multiple
               groups with different amount of events. WARNING: This should
               be used on grouped events.
    
           -F <freq>, --freq=<freq>
               Profile at this frequency. Use _max_ to use the currently
               maximum allowed frequency, i.e. the value in the
               kernel.perf_event_max_sample_rate sysctl.
    
           -i, --inherit
               Child tasks do not inherit counters.
    
           -k <path>, --vmlinux=<path>
               Path to vmlinux. Required for annotation functionality.
    
           --ignore-vmlinux
               Ignore vmlinux files.
    
           --kallsyms=<file>
               kallsyms pathname
    
           -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.