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SC_USAGE(1)                              BSD General Commands Manual                             SC_USAGE(1)

NAME
     sc_usage -- show system call usage statistics

SYNOPSIS
     sc_usage [-c codefile] [-e] [-l] [-s interval] pid | cmd | -E execute

DESCRIPTION
     sc_usage displays an ongoing sample of system call and page fault usage statistics for a given process
     in a ``top-like'' fashion.  It requires root privileges due to the kernel tracing facility it uses to
     operate.

     Page faults can be of the following types:
     PAGE_IN     page had to read from disk
     ZERO_FILL   page was created and zero filled
     COW         page was copied from another page
     CACHE_HIT   page was found in the cache

     The arguments are as follows:

     -c      When the -c option is specified, it expects a path to a codefile that contains the mappings for
             the system calls.  This option overrides the default location of the system call codefile which
             is found in /usr/share/misc/trace.codes.

     -e      Specifying the -e option generates output that is sorted by call count.  This overrides the
             default sort by time.

     -l      The -l option causes sc_usage to turn off its continuous window updating style of output and
             instead output as a continuous scrolling of data.

     -s      By default, sc_usage updates its output at one second intervals.  This sampling interval may be
             changed by specifying the -s option.  Enter the interval in seconds.

     pid | cmd | -E execute
             The last argument must be a process id, a running command name, or using the -E option, an exe-cution execution
             cution path followed by optional arguments.  The system call usage data for the process or com-mand command
             mand is displayed.  If the -E flag is used, sc_usage will launch the executable, pass along any
             optional arguments and display system call usage date for that executable.

     The data columns displayed are as follows:

     TYPE                      the system call type
     NUMBER                    the system call count
     CPU_TIME                  the amount of cpu time consumed
     WAIT_TIME                 the absolute time the process is waiting
     CURRENT_TYPE              the current system call type
     LAST_PATHNAME_WAITED_FOR  for each active thread, the last pathname that was referenced by a system
                               call that blocked
     CUR_WAIT_TIME             the cumulative time that a thread has been blocked
     THRD#                     the thread number
     PRI                       current scheduling priority

     The sc_usage command also displays some global state in the first few lines of output, including the
     number of preemptions, context switches, threads, faults and system calls, found during the sampling
     period.  The current time and the elapsed time that the command has been running is also displayed
     here.  The sc_usage command is also SIGWINCH savvy, so adjusting your window geometry may change the
     list of system calls being displayed.  Typing a `q' will cause sc_usage to exit immediately.  Typing
     any other character will cause sc_usage to reset its counters and the display.

SAMPLE USAGE
     sc_usage Finder -e -s2

     sc_usage will sort the Finder process usage data according to system call count and update the output
     at 2 second intervals.

SEE ALSO
     fs_usage(1), latency(1), top(1)

Mac OS X                                      October 28, 2002                                      Mac OS X