Red Hat Bugzilla – Bug 240073
cron should use inotify instead of constantly stat'ing files.
Last modified: 2015-01-04 17:29:49 EST
strace crond, and you'll see it wakes up once a minute to stat /etc/crontab, /etc/cron.d and /var/spool/cron to look if anything changed. This prevents the disk from ever spinning down when the system is otherwise idle. If crond used inotify to find out that these files/dirs changed, it wouldn't have to keep waking up at all.
Thanks for comment, I'm working on it in upstream and I'm planning after some testing push it to rawhide.
How's this work coming? This is a very small contributor to unnecessary wakeups, and with relatime it no longer keeps disks spun up either, but every little helps, especially in core features like the cron daemon that can't really be disabled.
I agree with you that's important feature. I rewrote the essential part of code, but there are still some features, options which don't work yet. I'm not sure if I make it to F-9 release, because I definitely don't want push untested package.
Changing version to '9' as part of upcoming Fedora 9 GA. More information and reason for this action is here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping