Re: port-xen/50659: Xen4.5 crash with vnds

[Christoph Badura <bad%bsd.de@localhost>]

On Wed, Mar 23, 2016 at 09:23:22AM +0100, Manuel Bouyer wrote:
> I think it is Xen's problem.
> I noticed that xen 4.5 starts domUs concurently (/etc/rc.d/xendomains start)
> which prevented be from upgrading to 4.5 because of concurency problems
> in my network scripts (local change).
> 
> Now if it runs scripts for each block device (or, I guess, each
> network device) in parallel, then we have a problem.

xl does indeed run the device hotplug scripts in parallel.  c.f.
libxl/libxl_device.c:device_hotplug().

If you looks at the linux hotplug scripts, they do their own serialization
as appropriate.  "grep -r _lock hotplug/Linux".

This is clearly a problem with the NetBSD hotplug scripts.  C.f.  pkg/51008.

--chris