9 Nov
2010
9 Nov
'10
9:03 p.m.
Dividing the imap processes's system CPU usage by number of imap processes:
imap : 0.478872 of 975 imap : 0.460797 of 1242 imap : 0.409641 of 2482 imap : 0.424035 of 4711 imap : 0.488494 of 6148 imap : 0.56809 of 7031 imap : 0.734864 of 6965
So it's about 0.5 seconds of system CPU per imap login. I also get something like 0.3 seconds of system CPU per imap login on my system.
Also setting:
service imap { service_count = 0 }
(i.e. reuse imap processes) reduced the system CPU usage to almost nothing. But if you use different UIDs for different users you can't do that.
So, yeah, looks like the process initialization is wasting time somewhere. I'll look further into it.