Re: udev sysfs docs Re: State of devfs in 2.6?

Ed Sweetman
2003-12-10T20:53:16Z

Ed Sweetman wrote:
> Witukind wrote:
>
>> On Wed, 10 Dec 2003 20:33:24 +0100
>> mru@kth.se (Måns Rullgård) wrote:
>>
>>
>>> Witukind <witukind@nsbm.kicks-ass.org> writes:
>>>
>>>
>>>> On Tue, 09 Dec 2003 10:39:32 +0100 mru@kth.se (Måns Rullgård) wrote:
>>>>
>>>>
>>>>>> Is there a specific case for which people want this feature?
>>>>>> Offhand it seems like a slightly odd thing to ask for...
>>>>>
>>>>>
>>>>> I believe the original motivation for module autoloading was to
>>>>
>>>>
>>>> save> memory by unloading modules when their devices were unused.
>>>> Loading> them automatically on demand made for less trouble for
>>>> users, who> didn't have to run modprobe manually to use the sound
>>>> card, or> whatever. This could still be a good thing in embedded
>>>> systems.>
>
> the biggest advantage from modules is the ability to enable/disable
> devices with different initialization configurations without rebooting,
> including the use of devices that aren't present during boot or may be
> added to a system that cant be put down to reboot. Embedded systems
> usually do not change, that's just part of being embedded, modules dont
> really make sense there unless things like filesystems and non-device
> modules never get used at the same time and memory is limited such that
> 100KB actually matters.
>
>
>>>> I don't see why it wouldn't be a good thing for regular systems
>>>> also. Saving memory is usually a good idea.
>
>
> True, but how about we start being good memory users where it counts the
> most, like gui's/userspace land and then worry about the sub 1MB usage
> that kernels exist in.
>
>>> The biggest modules are about 100k. Saving 100k of 1 GB doesn't
>>> really seem worth any effort.
>>
>>
>>
>> I don't have 1 Gb of memory. On my laptop with 16 mb RAM saving 100k
>> is worth
>> the effort.
>

Blah, scratch this.
> Then why do you use a sylpheed, which is gtk instead of something in a
> terminal that uses much less memory (doesn't require xfree86, which
> you're probably also using instead of tinyX) and toolkits, pixmaps etc.
> Obviously, 100k is not worth _your_ effort.

And of course that's all assuming you're using your laptop to write and
send email. Which you probably wouldn't be doing on a 16MB
laptop...probably wouldn't be doing anything on a 16MB laptop. But
anyway, the rest of what i was talking about is ok.

>
> I'm not saying module use is more memory efficient than not or vice
> versa, but if memory usage in the 100K range is going to be the only
> argument for autoloading/unloading of modules then it's really _not_
> worth the effort unless someone can give that kind of support without
> trying. Your fight for memory efficiency should start where the
> inefficiency is the largest, and work it's way down, not the other way
> around.
>