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

[christos%zoulas.com@localhost (Christos Zoulas)]

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

From: christos%zoulas.com@localhost (Christos Zoulas)
To: Manuel Bouyer <bouyer%antioche.eu.org@localhost>, Christoph Badura <bad%bsd.de@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 17:38:07 -0400

 On Mar 24, 10:34pm, bouyer%antioche.eu.org@localhost (Manuel Bouyer) wrote:
 -- Subject: Re: port-xen/50659: Xen4.5 crash with vnds
 
 | On Thu, Mar 24, 2016 at 10:22:36PM +0100, Christoph Badura wrote:
 | > On Thu, Mar 24, 2016 at 09:38:06PM +0100, Manuel Bouyer wrote:
 | > > > If you looks at the linux hotplug scripts, they do their own serialization
 | > > > as appropriate.  "grep -r _lock hotplug/Linux".
 | > > 
 | > > I tried to do something with shlock(1) but it doens't work, it's too
 | > > slow and xl times out. 
 | > > Maybe flock would work but older NetBSD don't have it ...
 | > 
 | > I noticed that you said before that shlock was too slow.  I'm surprised.
 | > The linux claim_lock functions calls out to perl...
 | 
 | the problem is that shlock can't wait on the lock by itself.
 | If it fail you have to retry, and in sh I didn't find a way to sleep
 | for less than 1s before retry (or you could busy-wait but I'm not sure
 | it's better).
 
 1. sleep 0.5 works
 2. there is also flock(1)
 
 christos