how to help (was Re: new shutdown order)

[David Young <dyoung%pobox.com@localhost>]

In addition to the below, it is important to convert all of the existing
shutdown hooks to PMF shutdown hooks.  That is, every hook registered
with shutdownhook_establish() should be replaced by a hook registered
with pmf_device_register1().

Dave

On Mon, Apr 20, 2009 at 06:54:37PM -0500, David Young wrote:
> Here are some ways to contribute to this on-going work:
> 
> 1 Write and test detach hooks for the disk pseudo-devices: ccd(4),
>   cgd(4), raid(4), vnd(4), et cetera.
> 
> 2 Add DVF_DETACH_SHUTDOWN to the CFATTACH_DECL()s if you know that it is
>   safe to detach it at shutdown.
> 
> 3 Make more drivers (safely) detachable.  Some drivers lack detach
>   hooks, or else detaching the driver remains problematic.
> 
>   * Drivers for PCI IDE controllers, such as piixide(4), are
>     not detachable: one reason why is that drivers do not
>     provide a "chip_unmap" counterpart to "chip_map" in struct
>     pciide_product_desc.
> 
>   Andrew Doran has detected a lot of problems with device detachment
>   already:
> 
>   * Interrupt and timecounter disestablishment have problems especially
>     on SMP and non-x86 systems:
> 
>         http://mail-index.netbsd.org/port-i386/2009/04/19/msg001326.html
>         
> http://mail-index.netbsd.org/source-changes-d/2009/04/08/msg000250.html
> 
>   * Detach hooks for PCI USB controllers have worrisome XXX comments,
> 
>         http://mail-index.netbsd.org/source-changes/2009/04/19/msg220094.html
> 
>   * pcppi(4) detachment is racy:
> 
>         
> http://mail-index.netbsd.org/source-changes-d/2009/04/08/msg000243.html
> 
> Dave
> 
> -- 
> David Young             OJC Technologies
> dyoung%ojctech.com@localhost      Urbana, IL * (217) 278-3933

-- 
David Young             OJC Technologies
dyoung%ojctech.com@localhost      Urbana, IL * (217) 278-3933