Incorrectly disabled php error handlers, causing site speed issues

We are having a problem on one of our sites whereby certain pages (I believe ones that are pulling in a lot of dynamic content) are experiencing extreme slowness. It isn’t consistent across the whole site, the rest of the site is pretty fast!

After speaking with our server guys, they say that the munmap process on the server has become very very slow, taking up 90% of the total time to display certain pages.

I found a solution online where someone was able to correct the problem after discovering incorrectly disabled php error handlers. But I am slightly reluctant to change anything within the PHP code (firstly, I don’t know where or what to change) and would like to enquire here first.

Has anyone else had this problem? Do you think it is EE related?

Many thanks in advance.