After inserting a half dozen timers into modules_rebuild_cache, I have found two functions that take 95% of the time:
drupal_system_listing takes almost 1/3 of the time - some of which is likely anti-vius,
drupal_alter('system_info'... took almost 2/3 of the time - and the only module using that is CVS_Deploy.
Turning off CVS_Deploy makes the page display on my PC almost within my memory span. But the production server also uses that module and runs in a second.
Nancy
Injustice anywhere is a threat to justice everywhere. -- Dr. Martin L. King, Jr.