Re: sysmon_envsys(9)

[Paul Goyette <paul%whooppee.com@localhost>]

On Mon, 25 Aug 2008, Quentin Garnier wrote:

> On Sun, Aug 24, 2008 at 10:16:08PM +0000, Paul Goyette wrote:
> > Several people have commented on various aspects of the current
> > sysmon_envsys(9) implementation and their desire to see it re-done for
> > NetBSD 5.0.  Many of these comments have been along the lines of "it
>
> No.  Definitely not for 5.0.  This is 6.0 stuff.

Yeah - typo.  Definitely 6.0.  :)

> > started out good but just grew to be too unwieldly."
> >
> > I've been tasked with getting sysmon_envsys(9) back under control.  I'd
> > appreciate any specific examples of this "bloat", or suggestions about
> > what's wrong with, or lacking in, the current implementation.  Hopefully,
> > what I come up with will be more useable without any of the excess baggage.
>
> While the API is probably better documented that the average kernel API,
> its inner workings are less documented.  There are situations where it
> is too clever for its own good:  for instance, it can get in the way of
> a slow-access ACPI embedded controller.  We might have done better since
> I last dared try it, but on one of my laptop I would get crashes or other
> issues when running xbattbar because its queries added to the monitoring
> thread in the kernel would either overwhelm the EC or more mundanely hit
> locking bugs within ACPI-CA.  One thing this example shows is that
> device drivers probably don't have enough control over how they can be
> accessed through the current API.

Thanks for discrete example.

----------------------------------------------------------------------
|   Paul Goyette   | PGP DSS Key fingerprint: |  E-mail addresses:   |
| Customer Service | FA29 0E3B 35AF E8AE 6651 |  paul%whooppee.com@localhost   |
| Network Engineer | 0786 F758 55DE 53BA 7731 | pgoyette%juniper.net@localhost |
----------------------------------------------------------------------