So I used amazing tool named KCacheGrind to parse XDebug output of MediaWiki. Of course, I immediately started refactoring some places in code. It is a random web hit, I don’t know even what it is, but it looks nasty and waiting for a gentle touch. Kill remote interwiki caches! :)
Here is what I got (triple click to zoom):
Yummy!
This is a bit scary.
Thats why MediaWiki applications take up quiet a lot of memory :/