Re: [PATCHSET 3/4] sysfs: divorce sysfs from kobject and driver model

Greg KH
2007-10-10T18:49:18Z

On Wed, Oct 10, 2007 at 11:26:32AM -0700, Martin Bligh wrote:
> Greg KH wrote:
>> On Wed, Oct 10, 2007 at 10:24:43AM -0700, Martin Bligh wrote:
>>>> The rules for sysfs files are the following:
>>>> - one value, in text format, per file.
>>>> - no action apon open/close
>>>> - binary files are only allowed for "pass-through" type files
>>>> that the kernel does not touch (like for firmware and pci
>>>> config space)
>>>> - directories should be associated with a kobject where it makes
>>>> sense (no nesting deep subdirectories without a kobject
>>>> present)
>>>> - when a directory is created/removed, a uevent should happen
>>>> declaring what type of device was created/removed.
>>> So you'll be removing:
>>>
>>> /sys/devices/system/node/node?/meminfo
>>>
>>> then?
>>>
>>> along with:
>>>
>>> /sys/devices/system/node/node?/distance
>>> /sys/devices/system/node/node?/numastat
>>>
>>> and all the other things that violate the rules?
>> I would love to do that :)
>> And that goes to show how trying to enforce these kinds of rules is damm
>> hard. Things slip by that I never notice because they are only for odd
>> types of hardware :)
>
> Is there no way to enforce that in the sysfs interface?
> (Haven't looked, I'll admit).

Hm, we could parse the buffer from the response and complain if we
notice spaces in it :)

>>> (which I do agree with ... I just don't think sysfs works for
>>> performance stats as we've discussed several times before ;-))
>> I agree that this doesn't work too, but also that if it's really needed,
>> it can be done, just let us know about it (like
>> /sys/block/BLOCKDEV/stat)
>
> OK. Would be nice if we could get rid of /sys/devices/system at
> some point, which seems like a fairly crazy path, but still ;-)

I agree, getting rid of the sysdev stuff is on the list of things I want
to see changed, that code is not nice...

thanks,

greg k-h