If you're on a Linux system, sysprof is your best friend.  First, make sure you've got the kernel development headers, and debugging information for the things you're trying to profile.  On a Fedora system, that looks like: 


[[!format txt """
% sudo yum -y install kernel-devel
% sudo debuginfo-install -y xorg-x11-server-Xorg xorg-x11-drv-savage
"""]]
Then, build sysprof: 


[[!format txt """
% git clone git://git.gnome.org/sysprof
% cd sysprof
% ./autogen.sh
% make
% sudo make install
% sudo sysprof &
"""]]
Click "Start", do some stuff, click "Profile", and revel in the glorious CPU time accounting. 

Note that sysprof is itself an X application, so you may want to run it forwarded to another display so it doesn't end up profiling its own animation.