The following reply was made to PR port-xen/34005; it has been noted by GNATS.

From: yamt@mwd.biglobe.ne.jp (YAMAMOTO Takashi)
To: gnats-bugs@NetBSD.org
Cc: port-xen-maintainer@netbsd.org, gnats-admin@netbsd.org,
	netbsd-bugs@netbsd.org
Subject: Re: port-xen/34005: xen3 loses bio requests?
Date: Mon, 16 Oct 2006 10:43:33 +0900 (JST)

 >  On Sat, Jul 15, 2006 at 05:15:00AM +0000, yamt@mwd.biglobe.ne.jp wrote:
 >  > 	after switching one of my machines from xen2 to xen3,
 >  > 	i occasionally (less frequently than once a day) see lwps in domU
 >  > 	stucking in "biowait", "vflushbuf".  (and "vnlock").
 >  > 	i guess in some cases bio requests get stuck or lost?
 >  > 
 >  > 	i haven't successfully checked if it was the whole xbd or just
 >  > 	some requests being stuck.
 >  > 
 >  > 	- it's a single processor machine.
 >  > 	- both of dom0 and domU are netbsd-current.
 >  > 	  (i haven't noticed the problem on linux domU yet,
 >  > 	  but it can be a matter of luck.)
 >  > 	- it used to work fine with xen2.
 >  
 >  Hi,
 >  could you try current with these changes:
 >  cvs rdiff -r1.12 -r1.13 src/sys/arch/xen/include/cpufunc.h
 >  cvs rdiff -r1.5 -r1.6 src/sys/arch/xen/include/xen3-public/io/ring.h
 >  
 >  It seems to fixe a similar hang in the network interface for me ...
 
 i don't think it can fix the problem for me as it's a single cpu machine.
 i can try it later but i don't have a recipe to reproduce the problem yet.
 
 YAMAMOTO Takashi