Upgrading modules process.

What goes on when upgrading modules during an upgrade of Gallery? The last two times I've done this it seems to take quite awhile, somewhere over 1 minute, and I can watch the CPU on the server getting more and more taxed.

Here's the output from uptime starting just shortly after I started upgrading the modules to just after it completed

12:27AM  up 44 days,  2:41, 2 users, load averages: 0.29, 0.23, 0.37
% uptime
12:27AM  up 44 days,  2:41, 2 users, load averages: 0.29, 0.23, 0.37
% uptime
12:28AM  up 44 days,  2:41, 2 users, load averages: 0.40, 0.26, 0.38
% uptime
12:28AM  up 44 days,  2:41, 2 users, load averages: 0.45, 0.27, 0.38
% uptime
12:28AM  up 44 days,  2:41, 2 users, load averages: 0.45, 0.27, 0.38
% uptime
12:28AM  up 44 days,  2:41, 2 users, load averages: 0.49, 0.28, 0.38
% uptime
12:28AM  up 44 days,  2:41, 2 users, load averages: 0.49, 0.28, 0.38
% uptime
12:28AM  up 44 days,  2:41, 2 users, load averages: 0.69, 0.33, 0.40
% uptime
12:28AM  up 44 days,  2:41, 2 users, load averages: 0.69, 0.33, 0.40
% uptime
12:28AM  up 44 days,  2:41, 2 users, load averages: 0.88, 0.37, 0.41
% uptime
12:28AM  up 44 days,  2:41, 2 users, load averages: 1.13, 0.43, 0.43
% uptime
12:28AM  up 44 days,  2:41, 2 users, load averages: 1.12, 0.44, 0.44
% uptime
12:28AM  up 44 days,  2:42, 2 users, load averages: 1.11, 0.45, 0.44
% uptime
12:28AM  up 44 days,  2:42, 2 users, load averages: 1.18, 0.48, 0.45
% uptime
12:28AM  up 44 days,  2:42, 2 users, load averages: 1.18, 0.48, 0.45
% uptime
12:28AM  up 44 days,  2:42, 2 users, load averages: 1.32, 0.52, 0.46
% uptime
12:28AM  up 44 days,  2:42, 2 users, load averages: 1.32, 0.52, 0.46
% uptime
12:28AM  up 44 days,  2:42, 2 users, load averages: 1.30, 0.52, 0.47
% uptime
12:28AM  up 44 days,  2:42, 2 users, load averages: 1.27, 0.53, 0.47
% uptime
12:29AM  up 44 days,  2:42, 2 users, load averages: 1.17, 0.52, 0.47
% uptime
12:29AM  up 44 days,  2:42, 2 users, load averages: 1.08, 0.51, 0.46
% uptime
12:29AM  up 44 days,  2:42, 2 users, load averages: 1.08, 0.51, 0.46
% uptime
12:29AM  up 44 days,  2:42, 2 users, load averages: 0.99, 0.51, 0.46
% uptime
12:29AM  up 44 days,  2:42, 2 users, load averages: 0.99, 0.51, 0.46
% uptime
12:29AM  up 44 days,  2:42, 2 users, load averages: 0.91, 0.50, 0.46