* Mark Moseley <moseleym...@gmail.com>: > > We're on 2.6.32 and the load only goes up when I change dovecot (not > > when I change the kernel, which I didn't do so far) > > If you at some point upgrade to >2.6.35, I'd be interested to hear if > the load skyrockets on you.
You mean even more? I'm still hoping it would decrease at some point :) I updated to 2.6.32-27-generic-pae today. I wonder what happens. > I also get the impression that the load average calculation in these > recent kernels is 'touchier' than in pre-2.6.35. Even with similar CPU > and I/O utilization, the load average on a >2.6.35 both is much higher > than pre- and it also seems to react more quickly; more jitter I guess. > That's based on nothing scientific though. Interesting. > Upping the client_limit actually results in less processes, since a > single process can service up to #client_limit connections. When I > bumped up the client_limit for imap, my context switches plummeted. Which setting are you using now? > Though as Timo pointed out on another thread the other day when I was > asking about this, when that proc blocks on I/O, it's blocking all the > connections that the process is servicing.Timo, correct me if I'm > wildly off here -- I didn't even know this existed before a week or > two ago. So you can then end up creating a bottleneck, thus why I've > been playing with finding a sweet spot for imap. Blocking on /proc? Never heard that before. > I figure that enough of a process's imap connections must be sitting in > IDLE at any given moment, so setting client_limit to like 4 or 5 isn't > too bad. Though it's not impossible that by putting multiple > connections on a single process, I'm actually throttiling the system, > resulting in fewer context switches (though I'd imagine bottlenecked > procs would be blocked on I/O and do a lot of volcs's). -- Ralf Hildebrandt Geschäftsbereich IT | Abteilung Netzwerk Charité - Universitätsmedizin Berlin Campus Benjamin Franklin Hindenburgdamm 30 | D-12203 Berlin Tel. +49 30 450 570 155 | Fax: +49 30 450 570 962 ralf.hildebra...@charite.de | http://www.charite.de
