Devel::NYTProf is a profiler for Perl programs that provides per-line and per-subroutine timing information. It generates HTML and CSV reports that help identify inefficient code. To use it, run a Perl program with -d:NYTProf and then generate reports with nytprofhtml or nytprofcsv for analysis. The profiler is fast and its reports integrate well with other tools like Kcachegrind for call graph visualization.

1. Profiling with Devel::NYTProf

2. Profiling Profiling: allows us to know what our programs are doing so we know where to optimize You actually need to profile before optimizing because you never know where the problems are going to be.

3. Devel::NYTProf: A History Devel::DProf Devel::SmallProf Old & broken! Has issues with current versions of Perl. Clock is too slow for current CPU times. Devel::FastProf Devel::NYTProf Versions 1, 2, 3 Hooray! Per line profiling Per line profiling but faster

4. Devel::NYTProf Why it's awesome * Profiles per: Line Subroutine Block * Inclusive & exclusive subroutine timing * Very fast * Awesome html reports (based on Devel::Cover) * Easy to use with mod_perl Devel::NYTProf::Apache

5. #Create nytprof.out: $ perl -d:NYTProf phone.cgi #Create nytprof directory & csv files: $ nytprofcsv Open .csv files in spreadsheet application or whatever Devel::NYTProf & nytprofcsv -d:foo executes the program under the control of a debugging, profiling or tracing module (e.g. Devel::foo)

6. nytprofcsv: Time per Line nytprofcsv: Time per Line Kinda icky

7. Devel::NYTProf & nytprofhtml Create nytprof.out: $ perl -d:NYTProf phone.cgi Create nytprof directory & html files: $ nytprofhtml Open ./nytprof/index.html

8. nytprofhtml: Top 15 Subroutines Links to source code Subroutine index with sortable columns

9. nytprofhtml: Top Packages Color coding based on median average deviation

10. nytprofhtml: Top Source Code Files

11. nytprofhtml: treemap

12. nytprofhtml: Time per Sub enter subroutine - leave subrountine Color coding relative to rest of file Annotates source code

13. nytprofhtml: Time per Line start of one statement to the next (;) expensive CPU & IO, too much detail

14. nytprofhtml: Time per Block Compromise

15. Kcachegrind Tool to generate and analyze callgraphs (graphs relationships between subroutines) Valgrind Cachegrind Callgrind Kcachegrind Memory debugging & profiling CPU cache profiler Cachegrind with call graphs GUI for Cachegrind

16. Devel::NYTProf & nytprofcg Currently NYTProf v.2 NYTProf v.3: nytprofcg! http://code.google.com/p/perl-devel-nytprof/source/checkout Creates callgraph data that can be read by Kcachegrind

17. Devel::NYTProf & nytprofcg Create nytprof.out: $ perl -d:NYTProf phone.cgi Create nytprof.callgraph $ nytprofcg Load callgraph into Kcachegrind $ kcachegrind nytprof.callgraph

18. Source Code & Callees Callees Source Code

19. Callee Map & Call Graph Percentage of time in each function Call graph Tree View

20. Devel::NYTProf::Apache Profile mod_perl! (Not supported on Windows) Add these guys to your apache conf file: PerlPassEnv NYTPROF PerlModule Devel::NYTProf::Apache nytprof.$$.out will end up in /tmp/ unless you specify otherwise by setting the NYTPROF environment variable file=

21. Resources http://en.oreilly.com/oscon2009/public/schedule/detail/7941 http://blog.timbunce.org/2008/07/15/nytprof-v2-a-major-advance-in-perl-profilers/ http://blog.timbunce.org/2009/08/07/nytprof-v3-a-sneak-peak/#more-301 http://code.google.com/p/perl-devel-nytprof/source/checkout CPAN!