NAME

       perfalloc - notify pmdaperfevent(1) to disable hardware counter allocation.

SYNOPSIS

       $PCP_PMDAS_DIR/perfevent/perfalloc [-D] [-d] [-f lockfile] [-h] [-v] [COMMAND]

DESCRIPTION

       perfalloc  is  a command that notifies the pmdaperfevent(1) to disable hardware counter event collection.
       This allow unprivileged processes to use the hardware counters.

       If the reservation request fails, then perfalloc exits  immediately  with  exit  code  EXIT_FAILURE.   If
       successful,  the  perfalloc  will  run until a kill signal is received.  The reservation request persists
       while perfalloc is running.

       Note that pmdaperfevent is affected by the value of the kernel.perf_event_paranoid setting, which can  be
       adjusted by sysctl(8).

       If a commandline is given, this is executed as a subprocess of the agent.  When the command dies, so does
       the agent.

       A brief description of the command line options follows:

       -D   run in the foreground (the default)

       -d   run in the background

       -f FILE
            use FILE as the lock file (default $PCP_PMDAS_DIR/perfevent/perflock)

       -h   display a help message and exit

       -v   output version number and exit

BUGS

       There may be a delay of up to 100 miliseconds between perfalloc requesting the hardware counter disabling
       and the perfevent PMDA processing the request.

       The  perfalloc  process  does  not check the status of the request and therefore is not able to provide a
       positive confirmation that the request succeeded and the hardware counters are disabled.

SEE ALSO

       pmdaperfevent(1), perfevent.conf(3) and sysctl(8).