Gentoo Archives: gentoo-user

From: Mark David Dumlao <madumlao@×××××.com>
To: gentoo-user@l.g.o
Subject: [gentoo-user] udev 140 showing spikes of cpu usage
Date: Mon, 30 Mar 2009 04:47:18
Message-Id: 6e2210230903292147t68deb59bld1a6efaa943c2f0b@mail.gmail.com
Hi guys,
Not particularly a show-stopper, but I recently did an emerge, and one
of the packages that was upgraded was udev. Intermittently, at least
since the upgrade, my udev has been giving me prolonged spikes of cpu
usage. It doesn't hog the whole cpu or anything, but it does use up
some 60-70% of my running cpu. This is when my actual CPU (3.0GHz P4
HT) is about 60-70% also, so the actual CPU% used by udev is something
close to maybe 25-30%. Normally, udev is about 6% of 60% though.

Now most of the time, just like now, I'm logged in to my PC from my
weaktop accross the room, and my other user, my brother, physically
sits on the machine, meaning there's two of us.  We've been doing this
for several months now without complaint, so I'm pretty sure it's good
enough to handle us both. However, recently, at least since my last
emerge, my brother says that the responsiveness sometimes goes down at
certain points and when I go top from across the room I see udev going
to about 60-something mph. So what I do is I just restart udev, music
dies for about half a second, but everything goes back immediately
without problems. Essentially painless.

The second time I had to restart udev I suspected something was wrong,
so I set my udev.conf to go
udev_log="err info debug"
And restarted it.

So the third and fourth time udev gave me a spike, I checked my system
logs for anything related. Nope, nothing doing.

This usually only happens when my other user is around, not when I'm
just sitting across the room. Most of what we do is just firefox,
although just recently I've been using digikam (which takes forever to
start up because of the sheer size of my pictures collection, but hey,
I'm not one to complain).

I figure this may probably be related to my udev version bump. I
forget my previous version, so it might be even a lower version bump
than 140. Or maybe it's been going on for a while and I just didn't
notice it. Anyhows, has anyone (if anyone has) noticed any strange
udev CPU activity before? What have your experiences been with it and
what do you think it's usually related to?

=== some out-of-the-ordinary things that might be related, but I don't think so
- we did buy a new hard drive just last month. No problems with that one so far.
- now that I think of it, my xorg drivers and other stuff probably
also got bumped with udev.
- i've been ignoring a bunch of tracker segmentation faults in my
/var/log/messages, related to extracting exifs
- a bunch of samba shares
- we haven't logged out of our xsession in about a week.