i read your article and it’s been very informative.. when i profiled the symfony project i found several entries in the list..

i couldn’t see any cycles in your graph so i wonder if there’s something really f**** up in our configuration or it’s not unusual to have cycle entries (sfFilterChain->execute -> sfCommonFilter->execute -> -> sfFilterChain->execute.. that’s somehow weird.. and i don’t think that’s how the output of cachegrind should look like

I for myself usually don’t use any specific tools for profiling (at least until now). What helped most for me were always a small series of actions:
* Optimize SQL queries: the queries themselves can be optimized e.g. using indexes. Caching hydrated objects during a script call if they are requested several times also really helps. For tables that hold data that is requested quite often it may be helpful to load all the entries everytime one is requested.
* Optimize the user experience, mostly by packing tons of CSS and JS includes into as little files as possible. The same goes for images (e.g. icons): packing them into 1 big image and selecting the desired icon by offsetting the position inside the image is very powerful and quite easy using CSS. Decreasing web server connections increases the performance both for the user and on your server (less connections required).