Mark Moseley put forth on 12/9/2010 12:18 PM:
If you at some point upgrade to >2.6.35, I'd be interested to hear if the load skyrockets on you. I also get the impression that the load average calculation in these recent kernels is 'touchier' than in pre-2.6.35.
This thread may be of value in relation to this issue:
http://groups.google.com/group/linux.kernel/browse_thread/thread/eb5cb488b74...
It seems there are some load issues regarding recent Linux kernels, from 2.6.34 (maybe earlier?) on up. The commit of the patch to fix it was Dec 8th--yesterday. So it'll be a while before distros get this patch out.
However, this still doesn't seem to explain Ralf's issue, where the kernel stays the same, but the Dovecot version changes, with 2.0.x causing the high load and 1.2.x being normal. Maybe 2.0.x simply causes this bug to manifest itself more loudly?
This Linux kernel bug doesn't explain the high load reported with 2.0.x on FreeBSD either. But it is obviously somewhat at play for people running these kernels versions and 2.0.x. To what degree it adds to the load I cannot say.
-- Stan