Re: [Fwd: Recommendation for activating a deferred module init in the kernel]

[Pavel Machek <pavel@suse.cz>]

Hi!

> In our modification, we:
>  1) add another phase for deferred initcalls
>  2) modify the module_init macro definition to use that phase, for the
>  modules we wish to defer initialization of
>  3) modify the free code to not free the memory until later
>  4) add an ioctl to trigger the deferred initialization (and memory free)
> 
> One of the main sub-systems that we defer initialization of this
> way is USB, and this saves quite a bit of time.  (Of course the
> same, or slightly more CPU cycles are eventually used during
> bootup time.  But this lets us get to user space quicker so we
> can start user-visible applications faster.)

Could the usb be modified to do background init by default, instead?

> I'm not that happy using an ioctl for this trigger.  What is
> the preferred method of activating a kernel feature like this?
> I presume something in /proc or /sys, but I'm not sure.

Definitely not /proc.

							Pavel
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