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

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

The following reply was made to PR kern/50659; it has been noted by GNATS.

From: Christoph Badura <bad%bsd.de@localhost>
To: Manuel Bouyer <bouyer%antioche.eu.org@localhost>
Cc: gnats-bugs%netbsd.org@localhost, kern-bug-people%netbsd.org@localhost,
	gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost,
	sebastian%xenoserver.net@localhost
Subject: Re: port-xen/50659: Xen4.5 crash with vnds
Date: Thu, 24 Mar 2016 18:53:20 +0100

 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