Re: udev is too slow creating devices

[Andrea Arcangeli]

On Wed, Sep 15, 2004 at 09:15:41AM -0700, Greg KH wrote:
> But the low level driver (like a USB driver for example), has no way of
> knowing when the "device discovery" process is over.  Actually the USB
> core never knows this either, as devices come and go all the time.

eventually the discovery will end with a call into userspace, it'd be
enough to wait4 and wakeup a waitqueue when the wait4 returns. 

> So the kernel can not know what or when to wait for something it doesn't
> know is going to ever happen in the future.

the kernel certainly knows when it's about time to fork an userspace
process to create the device, doesn't it? then just wait4 while the
process is running.

> Remember, this isn't your old "static device tree" unix-like kernel that
> people grew up with, anymore. :)

if you intentionally don't want to provide serialization and force into
/var/run locking, that's fine with me, but I don't buy your claim that
it's not feasible.
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