Code profiling with Xdebug and Kcachegrind

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Robert Basic ~ phpbenelux17 Code profiling with Xdebug and KCachegrind Robert Basic https://robertbasic.com/ @robertbasic

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Robert Basic ~ phpbenelux17 Tools of the trade Xdebug ● Not just for debugging KCachegrind ● Visualizing profiling data

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Robert Basic ~ phpbenelux17 What’s the fastest code?

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Robert Basic ~ phpbenelux17 The code that’s not called!

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Robert Basic ~ phpbenelux17 Number of calls

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Robert Basic ~ phpbenelux17 Who’s to blame?

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Robert Basic ~ phpbenelux17 Which was called by another method

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Robert Basic ~ phpbenelux17 Which was called by another method

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Robert Basic ~ phpbenelux17 So many callers!

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Robert Basic ~ phpbenelux17 A graph to see it

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Robert Basic ~ phpbenelux17 Context to understand it

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Robert Basic ~ phpbenelux17 Fix it This is really up to you

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Robert Basic ~ phpbenelux17 Tips for fixing performance issues ● Biggest impact, least effort ● Profile after every change ● Avoid over-optimizing ● Learn to EXPLAIN

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Robert Basic ~ phpbenelux17 Tips for using Xdebug and KCachegrind ● Xdebug – xdebug.profiler_output_dir – xdebug.profiler_output_name – cachegrind.out.%t.%R – Xdebug lies! ● KCachegrind – Install graphviz – Use % relative – Turn on Cycle detection – Settings > Configure KCachegrind > Annotations > Add source folder

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Robert Basic ~ phpbenelux17 Other tools ● WinCacheGrind, Webgrind ● XHProf ● Blackfire.io

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Robert Basic ~ phpbenelux17 Thanks! Questions?