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TPROF(8)                    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 incompatible
     way.

NetBSD 6.1.5                   November 26, 2011                  NetBSD 6.1.5