>  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