The Perl 5 module Devel::NYTProf is a powerful feature-rich perl
source code profiler.
- Performs per-line statement profiling for fine detail
- Performs per-subroutine statement profiling for overview
- Performs per-block statement profiling (the first profiler to do so)
- Accounts correctly for time spent after calls return
- Performs inclusive and exclusive timing of subroutines
- Subroutine times are per calling location (a powerful feature)
- Can profile compile-time activity, just run-time, or just END time
- Uses novel techniques for efficient profiling
- Sub-microsecond (100ns) resolution on systems with clock_gettime()
- Very fast - the fastest statement and subroutine profilers for perl
- Handles applications that fork, with no performance cost
- Immune from noise caused by profiling overheads and I/O
- Program being profiled can stop/start the profiler
- Generates richly annotated and cross-linked html reports
- Trivial to use with mod_perl - add one line to httpd.conf
- Includes an extensive test suite
- Tested on very large codebases
NyTProf is effectively two profilers in one: a statement profiler,
and a subroutine profiler.

Homepage:
https://metacpan.org/release/Devel-NYTProf
