Profiling login? & .xsession-errors

[Adam Tauno Williams <awilliam whitemice org>]

Logging into openSUSE 12.2 x86_64 GNOME 3.6 can be a bit slow.  The
hard-drive activity light is on solid for quite some time.

Is is possible to somehow profile login?  To record that is happening
and some estimate of how long it takes?

Also, related, the .xsession-errors log file doesn't contain any
timestamps.  That makes it difficult to go back and relate a message to
an event.  Is there any way to enable timestamps in .xsession-error
messages?