Bug 181590 - [vm] [panic] amd(8) related vm_page_unwire panics
Summary: [vm] [panic] amd(8) related vm_page_unwire panics
Status: Open
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: Unspecified
Hardware: Any Any
: Normal Affects Only Me
Assignee: freebsd-bugs mailing list
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2013-08-27 22:10 UTC by kamikaze
Modified: 2017-12-31 22:27 UTC (History)
0 users

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Description kamikaze 2013-08-27 22:10:00 UTC
I have textdumps for two vm_page_unwire panics.

The first one occurred while copying data from one msdosfs to another,
both mounted through amd:

http://pastebin.com/bVgmmcv1

The second one happened when SIGTERM was sent to amd, while there was
heavy tmpfs load (building chromium). No file systems were mounted through
amd at the time:

http://pastebin.com/uqgMiGPc

The second case is easy to reproduce, I have a 100% panic quota for this
scenario.

The core trouble is that the issue even occurs /after/ there was heavy
tmpfs load in the past, while amd was running. Again without any actual
mounts happening. So there is a panic for every system shutdown/reboot.

How-To-Repeat: Set WRKDIRPREFIX to a tmpfs (I do not know whether the tmpfs is necessary,
but it certainly helps avoiding excessive filesystem damage).

# cd /usr/ports/www/chromium
# make

Wait till the configure phase is over and the port is actually compiling.

# service amd stop
While chromium is still compiling.
Comment 1 Peter Holm 2013-09-02 07:13:10 UTC
I have not been able to reproduce this panic.
Suggested adding "-S" to amd(8) as a workaround.
-- 
Peter
Comment 2 kamikaze 2013-09-02 08:15:59 UTC
On 02/09/2013 08:13, Peter Holm wrote:
> I have not been able to reproduce this panic.

Well, thank you for trying any way!

> Suggested adding "-S" to amd(8) as a workaround.

Done already:
http://svnweb.freebsd.org/ports/head/sysutils/automounter/Makefile?revision=325726&view=markup

Can I somehow provide more useful data? Maybe my use of nullfs also plays
a part.

> mount -p
/dev/ufs/5root		/			ufs	rw,noatime 	1 1
devfs			/dev			devfs	rw,multilabel 	0 0
/dev/ufs/5stor		/pool/5stor		ufs	rw,noatime 	2 2
/pool/5stor/usr		/usr			nullfs	rw,noatime 	0 0
/pool/5stor/var		/var			nullfs	rw,noatime 	0 0
/usr/home/root		/root			nullfs	rw,noatime 	0 0
tmpfs			/var/log		tmpfs	rw		0 0
tmpfs			/var/run		tmpfs	rw		0 0
tmpfs			/tmp			tmpfs	rw		0 0
pid62791@mobileKamikaze:/var/run/automounter.amd.mnt /var/run/automounter.amd.mnt nfs	rw		0 0

From my make.conf:
.if !${.CURDIR:M/tmp/obj/*}
WRKDIRPREFIX=           /tmp/obj/${HOST}/${ARCH}
.endif

-- 
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?
Comment 3 Eitan Adler freebsd_committer freebsd_triage 2017-12-31 07:59:43 UTC
For bugs matching the following criteria:

Status: In Progress Changed: (is less than) 2014-06-01

Reset to default assignee and clear in-progress tags.

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