Re: [RFC] EDAC and the sysfs

[Doug Thompson <norsk5@yahoo.com>]

--- Greg KH <greg@kroah.com> wrote:

> On Tue, Nov 15, 2005 at 04:26:38PM -0800, Doug
> Thompson wrote:

> > My question is:  Should I remove entirely my old
> > /proc/sys/mc sysctl tree? Or still maintain the
> > aliases there (which seems weird)? 
> 
> That would be wierd, just drop the sysctl stuff.
> 
> > If I do that, then /etc/sysctl.conf will no longer
> > allow for setting things up there.
> 
> True.
> 
> > Is there going to be a similiar functionality as
> > /etc/sysctl.conf for those items we place in
> sysfs, in
> > the future?
> 
> If you want to write one, sure :)

Good idea. Seems I have hit the edge of current
features. That's is good for now there is another food
item for a TODO list.

> 
> But you can just probably use a udev rule to
> initialize your things
> properly, that's what all of the distros are now
> using.

Ok. That's another area for me to research. edac does
not have any /dev/ entries, just the files and
controls previous mentioned. 

So, from your comment then, udev has some mechanism to
set controls in sysfs?


> 
> > PS. These questions on sysfs seem a perfect food
> > stream for your 'HOWTO do kernel development'.
> Trying
> > to do new entries in sysfs has been a painstaking
> > adventure. After googling the web for info, it
> > definitely has been a bit thin on information on
> sysfs
> > at the level I am seeking.
> 
> sysfs and the driver model are woefully
> underdocumented.  Right now, I'd
> recommend the Linux Device Drivers, third edition,
> free online if you
> don't want to buy it, for anyone doing any driver
> core stuff.  It has a
> whole chapter that is the most up-to-date and the
> best description I've
> seen so far.

Yes, I have LDD 3rd and it is good. I have also have
Robert Love's book and it has some good stuff on the
device model and sysfs, but I assume since the whole
feature is fairly new its documentation and
understanding are still in the nursery.

I also came across Patrick Mochel's paper given at
Linux Symposium in June 2005. That helped.

>From the src on the machinecheck currently in sysfs, I
see it implements the 'subsystem' feature of sysfs.
>From that code I see the pattern I can use.

> 
> But even then, it is out of date, due to api
> changes, sorry.
> 
> thanks,
> 
> greg k-h
> 

at least there is some docs AND some people to ask
questions to.

thanks

doug t



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