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).