Re: [PATCH v4] driver core: shut down devices asynchronously

[Greg Kroah-Hartman]

On Thu, Sep 21, 2023 at 11:34:43AM -0500, Stuart Hayes wrote:
> Shut down devices asynchronously, ensuring that each device is shut down
> before its parents.
> 
> This can dramatically reduce system shutdown/reboot time on systems that
> have devices that take many seconds to shut down, such as some NVMe drives.
> On one system tested, the shutdown time went from 11 minutes without this
> patch to 55 seconds with the patch.

That's a nice improvement, but I think we need a lot more testing on a
wide range of systems before we can take a patch like this.

Also, what about busses that don't want this type of shutdown?  We allow
busses to opt-in for async probing, shouldn't that be also done for
shutting them down to resolve issues for busses that can not handle
this?

thanks,

greg k-h