Hello Songbo, On Mon, 2024-04-01 at 13:32 +0200, Songbo Wang wrote: > Hi, > > I am running an OpenSMTPD server with opensmtpd-filter-dkimsign-0.5p2 on > OpenBSD 7.4 (amd64). I noticed recently that the dkimsign program was using a > lot of memory: > > $ ps ax -orss,command | grep dkimsign > 110920 /usr/local/libexec/smtpd/filter-dkimsign -d wsb.onl -s viper1 -k > /etc/mai > 304 grep dkimsign > > I am not a C programmer so maybe I am wrong, but it seems to me that over 100 > MB is a lot for the simple program.
I'm aware of this, and I've also managed to track the reason down. I haven't spend the time yet to find a good solution yet. The problem is that after every line libopensmtpd does an event_del/ event_add dance, which libevent queues up for the next kqueue call without doing any deduplication. This means that if it receives a lot of lines to send before returning to the event loop (which happens when you flush a complete cached file from /tmp as dkimsign does) it can grow to an unreasonable amount of kqueue events. The second part of the problem is that this array is never freed/shrunk by libevent. So it shouldn't grow further, unless you sign even larger mails, but I agree that it's far from ideal. > > And of course the relevant line in my smtpd.conf is the following: > > filter "dkimsign" proc-exec "filter-dkimsign -d wsb.onl -s viper1 \ > -k /etc/mail/dkim/private.key" user _dkimsign group _dkimsign > > I am not sure if this memory usage is related to how long the program is > being ran (server’s uptime is over 100 days), so I didn’t restart the > dkimsign program to investigate. But I will be happy to provide more > information if needed. > > Thanks, > -- > Songbo Wang > martijn@
