Subject: Re: imon in NetBSD?
To: None <>
From: David Young <>
List: tech-kern
Date: 01/08/2005 18:52:40
On Sat, Jan 08, 2005 at 11:49:23PM +0100, Julio M. Merino Vidal wrote:
> Hi all,
> I've been adding kqueue support to famd, but it looks like to be less
> than optimal (it can be useful for a desktop system, but not much more).
> There are multiple problems with kqueue when it comes to achieve similar
> imon behavior as seen in the following link:

FWIW, I thought that the first reply in this thread dispelled a lot of
concerns and answered most of the questions.

Something I did not understand is why the VFS layer does not already
issue the kevent notifications.

> Also there is one other serious issue.  kqueue works by monitoring open
> file descriptors, while imon works with path names.  So imon can easily
> monitor a big amount of files, but doing the same thing with kqueue can
> be problematic (you need to increase kern.maxfiles).  Just consider

I have always thought that the way to solve this is to extend the vnode
kevents to make them optionally "heritable" by the vnodes in the subtree,
and then extend the "kdata" to tell me the affected path in the subtree.
Now I can listen on one kevent descriptor for events on the whole subtree.
I don't claim to know whether/how that heritability will work.


David Young             OJC Technologies      Urbana, IL * (217) 278-3933