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.