Subject: port-xen/34005: xen3 loses bio requests?
To: None <,,>
From: None <>
List: netbsd-bugs
Date: 07/15/2006 05:15:00
>Number:         34005
>Category:       port-xen
>Synopsis:       xen3 loses bio requests?
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-xen-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Jul 15 05:15:00 +0000 2006
>Originator:     YAMAMOTO Takashi <>
>Release:        NetBSD 3.99.21

System: NetBSD kaeru 3.99.21 NetBSD 3.99.21 (build.kaeru.xen3) #23: Wed Jul 12 21:58:30 JST 2006 takashi@kaeru:/home/takashi/work/kernel/build.kaeru.xen3 i386
Architecture: i386
Machine: i386
	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.