Re: fifo and [acm]time

[Taylor R Campbell <campbell+netbsd-tech-kern%mumble.net@localhost>]

   Date: Mon, 26 Dec 2011 18:35:34 +0000
   From: Mouse <mouse%Rodents-Montreal.ORG@localhost>

   >> Is one inode update per minute enough to be a significant issue?
   > It means the disk must continue spinning and, e.g., will continue to
   > draw power from a laptop battery to do so, even when the system is
   > functionally idle.

   Aren't there lots of things that already do that?

There are a few.  It would be nice if users of laptops or devices with
limited flash storage had an easy way to suppress all of them, without
having to wade through configuration files and configure mfs or tmpfs
instances for Postfix and whatnot.  And in a vanilla NetBSD install,
mounting file systems noatime and nodevmtime does suffice to suppress
most of them.

Postfix remains the highest-frequency perpetrator of disk I/O,
triggering an mtime update every minute.  The second highest is cron,
which runs atrun every ten minutes and logs the fact to /var/log/cron.

Perhaps there should be another mount flag nofifomtime, or perhaps
nodevmtime should inhibit fifo [acm]time updates too.