xrprof1

Usage

Overview

A sampling profiler for R(1) programs. xrprof writes to standard output the Rprof.out format widely used by existing R-based tools.

Options

Malformed arguments will fall back on the defaults, if possible.

-h

Print usage and exit.

-p PID

Specify the pid of the target R program.

-F FREQ

Set the sampling frequency, in Hertz. The default is 1 Hz, i.e. one sample per second, and the maximum is 1000 Hz (though far fewer samples are usually required).

-d DURATION

Set the duration for xrprof to take samples before exiting (provided the target program runs that long). The default is to last up to one hour.

-o FILE

Write output to FILE instead of standard output.

-m

Run in “mixed mode”, where samples are drawn from both the R-level and native C/C++ stacks and collated together.

Examples

Sample from an existing R program for 5 seconds at a useful frequency:

    $ xrprof -F 50 -d 5 -p `pidof R`

Start a new R program in the background and then start the profiler, writing samples to the file Rprof.out in the current directory:

    $ Rscript myprogram.R &
    $ xrprof -F 50 -p $! > Rprof.out

Exit status

0

Successful program execution.

1

A fatal error ocurred during sampling.