TPROF(8)						    BSD System Manager's Manual 						  TPROF(8)

NAME

     tprof -- record tprof profiling samples

SYNOPSIS

     tprof [-c] [-o file] command ...

DESCRIPTION

     The tprof is a sampling based profiler.

     tprof utility makes the kernel driver start profiling, executes the specified command, keeps recording samples from the kernel driver until
     the command finishes, and reports statistics to the standard error.

     The tprof pseudo driver and a suitable backend should be loaded beforehand.

     The tprof utility accepts the following options.

     -o file   Write the collected samples to the file named file.  The default is ``tprof.out''.

     -c        Write the collected samples to the standard output.  Note that the output is a binary stream.

EXAMPLES

     The following command profiles the system during 1 second and shows the top-10 kernel functions which likely consumed CPU cycles.

	     tprof -c sleep 1 2>/dev/null | tpfmt -skCLP | head -10

DIAGNOSTICS

     The tprof utility reports the following statistics about the activities of the tprof pseudo driver.

     sample	      The number of samples collected and prepared for userland consumption.

     overflow	      The number of samples dropped because the per-CPU buffer was full.

     buf	      The number of buffers successfully prepared for userland consumption.

     emptybuf	      The number of buffers which have been dropped because they were empty.

     dropbuf	      The number of buffers dropped because the number of buffers kept in the kernel exceeds the limit.

     dropbuf_samples  The number of samples dropped because the buffers containing the samples were dropped.

SEE ALSO

     tpfmt(1), tprof(4)

AUTHORS

     The tprof utility is written by YAMAMOTO Takashi.

CAVEATS

     The contents and representation of recorded samples are undocumented and will likely be changed for future releases of NetBSD in an incompat-
     ible way.

BSD
								 November 26, 2011							       BSD