Finding CPU bottleneck in shared libraries

[no_hope]

I am having some performance issues in X because of using 3 monitors and xinerama. I'd like to see if gcc's profile-directed optimization will improve performance. To do this, I need to know which library or libraries are responsible for most CPU usage. Does anybody know how to do this?

For example, top tells me that the process X is hogging the CPU, but I need to know which shared libraries are actually responsible for CPU usage (e.g. libXinerama or libX11, etc.) before I can try to optimize them.

Thanks!

[frostschutz]

man gprof

it's per routine and not per library though, so you'll probably have to look at the source code as well and find out where the responsible routine is located