pmc(1) - NetBSD Manual Pages

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PMC(1)                  NetBSD General Commands Manual                  PMC(1)


NAME

     pmc -- performance-monitoring counter interface


SYNOPSIS

     pmc command [arguments]


DESCRIPTION

     The pmc tool can be used to control and inspect the state of the Perfor-
     mance-Monitoring Counters (PMCs) in the system.

     The first argument, command, specifies the action to take.  Valid com-
     mands are:

     list     Display a list of performance counter events available on the
              system.

     start name:option [name:option ...]
              Start one or several counters.  name specifies the name of the
              event to count; it must be taken from the list of available
              events.  option specifies the source of the event; it must be a
              combination of u (userland) and k (kernel).

     stop     Stop any performance counters that are currently running, and
              display the values of these counters.


FILES

     src/sys/arch/x86/x86/pmc.c x86 implementation.

     src/usr.bin/pmc/pmc.c pmc tool.


EXAMPLES

     The following command prints the available counters.
           # pmc list

     The following command starts two counters.  The former will count the
     'l2cache-access' events that are triggered from userland, the latter will
     count the 'l1cache-access' events triggered from both userland and the
     kernel.
           # pmc start l2cache-access:u l1cache-access:uk

     Note that the two following commands are not exactly identical.
           # pmc start l1cache-access:u l1cache-access:k
           # pmc start l1cache-access:uk
     The former will start two different counters that have a different source
     but track the same event.  The latter will start one counter that tracks
     the event from all sources; it therefore does the sum of the two counters
     from the first command, but takes only one counter to do so.


INTERPRETING RESULTS

     For each PMC on each CPU, the value reported by the pmc tool is the num-
     ber of events counted, encoded in a 64bit integer.


DIAGNOSTICS

     PMC support not compiled into the kernel  Performance-monitoring counter
     support has not been compiled into the kernel.  It may be included using
     the PMC option.  See options(4) for details.


SEE ALSO

     options(4)


HISTORY

     The pmc command first appeared in NetBSD 1.6.  It was revamped in
     NetBSD 8.0.


BUGS

     The pmc command currently only supports performance-monitoring counters
     on the i386 and amd64 architectures.

NetBSD 8.3                       July 12, 2017                      NetBSD 8.3