Re: CVS commit: src/sys/arch/x86/x86

[Marc Balmer <mbalmer%NetBSD.org@localhost>]

Am 18.10.11 13:44, schrieb Iain Hibbert:
> On Tue, 18 Oct 2011, Jukka Ruohonen wrote:
> 
>> On Tue, Oct 18, 2011 at 06:39:49AM -0400, Jared McNeill wrote:
>>> I would argue that any manually loaded module shouldn't be autounloaded.
>>> What do you think about flagging modules as autoloaded and only
>>> autounloading the autoloaded ones?

When I manually load gpiosim, it will autoload gpio.  Now when I
manually modunload gpiosim, gpio will stay there.  But in this case, I
want gpio to be autounloaded eventually.

>>
>> That sounds right to me.
>>
>> As noted, generally I am not sure what my opinion about autounloading really
>> is. But it feels somewhat awkward and error-prone that drivers must "protect"
>> themselves against the autounloading kthread.
> 
> How often is autounloading actually effectively used anyway?  I mean, if
> the module is loaded automatically, it is because the system found that it
> was needed.
> 
> So, yes.. there situation where eg USB or PCMCIA devices might have a
> transient need for a driver, but on the other hand, the overhead of a
> driver being in memory is not that great considering that you used it
> once, as the chance of re-use is significant (higher by far than all the
> other drivers that have never been needed)
> 
> The real benefit of the modular system is that you don't need to load
> hundreds of modules on the off chance that they will be used. A cron entry
> could be used to flush unused modules if the sysop cares about that, why
> do we need a kthread running?
>