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 over-
	     rides 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 execution path followed by optional argu-
	     ments.  The system call usage data for the process or command is displayed.  If the -E flag is used, sc_usage will launch the exe-
	     cutable, 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