From: Keir Fraser <keir.xen@gmail.com>
To: Sander Eikelenboom <linux@eikelenboom.it>,
Santosh Jodh <santosh.jodh@citrix.com>,
wei.wang2@amd.com
Cc: "xen-devel@lists.xen.org" <xen-devel@lists.xen.org>
Subject: Re: Using debug-key 'o: Dump IOMMU p2m table, locks up machine
Date: Sun, 02 Sep 2012 08:42:15 +0100 [thread overview]
Message-ID: <CC68CC67.3D984%keir.xen@gmail.com> (raw)
In-Reply-To: <647712821.20120831234512@eikelenboom.it>
On 31/08/2012 22:45, "Sander Eikelenboom" <linux@eikelenboom.it> wrote:
>
> I was trying to use the 'o' debug key to make a bug report about an "AMD-Vi:
> IO_PAGE_FAULT".
>
> The result:
> - When using "xl debug-keys o", the machine seems in a infinite loop, can
> hardly login, eventually resulting in a kernel RCU stall and complete lockup.
We don't defer the key handler to tasklet context in this case (because of
'if !in_irq()' check in keyhandler.c:handle_keypress()). Hence the dom0 vCPU
gets 'stuck' while the handler executes. Possibly we should always defer
non-irq keyhandlers to tasklet context, even when executed via sysctl.
> - When using serial console: I get a infinite stream of "gfn: mfn: " lines,
> mean while on the normal console, S-ATA devices are starting to give errors.
In this case the handler must be running in tasklet context. Not sure why
SATA interrupts would be affected as hardirq and softirq work will still be
carried out during execution of the keyhandler (the handler voluntarily
preempts itself for softirq work).
Would need more investigation. :)
-- Keir
> So either option trashes the machine, other debug-keys work fine.
>
> Machine has a 890-fx chipset and AMD phenom x6 proc.
>
> xl dmesg with bootup and output from some other debug-keys is attached.
>
> --
>
> Sander
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
next prev parent reply other threads:[~2012-09-02 7:42 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-31 21:45 Using debug-key 'o: Dump IOMMU p2m table, locks up machine Sander Eikelenboom
2012-08-31 22:24 ` Santosh Jodh
2012-08-31 22:42 ` Sander Eikelenboom
2012-08-31 22:57 ` Santosh Jodh
2012-08-31 23:16 ` Sander Eikelenboom
2012-08-31 23:58 ` Santosh Jodh
2012-09-01 0:42 ` Santosh Jodh
2012-09-03 8:14 ` Jan Beulich
2012-09-01 2:01 ` Keir Fraser
2012-09-01 17:03 ` Santosh Jodh
2012-09-01 19:13 ` Keir Fraser
2012-09-02 2:08 ` Santosh Jodh
2012-09-02 7:13 ` Keir Fraser
2012-09-02 7:19 ` Keir Fraser
2012-09-02 8:43 ` Sander Eikelenboom
2012-09-02 14:58 ` Keir Fraser
2012-09-02 15:14 ` Sander Eikelenboom
2012-09-03 15:20 ` Wei Wang
2012-09-04 8:21 ` Sander Eikelenboom
2012-09-04 16:43 ` Sander Eikelenboom
2012-09-05 10:14 ` Jan Beulich
2012-09-05 10:25 ` Sander Eikelenboom
2012-09-05 10:40 ` Jan Beulich
2012-09-05 10:48 ` Sander Eikelenboom
2012-09-05 11:41 ` Jan Beulich
2012-09-05 12:11 ` Sander Eikelenboom
2012-09-05 14:15 ` Wei Wang
2012-09-05 15:05 ` Jan Beulich
2012-09-05 12:48 ` Wei Wang
2012-09-05 12:30 ` Wei Wang
2012-09-03 8:21 ` Jan Beulich
2012-09-03 8:33 ` Sander Eikelenboom
2012-09-03 9:05 ` Jan Beulich
2012-09-04 7:08 ` Sander Eikelenboom
2012-09-04 7:46 ` Jan Beulich
2012-09-04 8:13 ` Sander Eikelenboom
2012-09-04 9:26 ` Jan Beulich
2012-10-02 20:09 ` Konrad Rzeszutek Wilk
2012-10-03 13:12 ` Jan Beulich
2012-10-02 20:54 ` Matt Wilson
2012-09-20 8:08 ` Jan Beulich
2012-09-28 14:08 ` Sander Eikelenboom
2012-09-28 21:26 ` Jeremy Fitzhardinge
2012-10-02 20:08 ` Konrad Rzeszutek Wilk
2012-09-02 7:42 ` Keir Fraser [this message]
2012-09-04 6:35 ` Jan Beulich
2012-09-04 6:52 ` Sander Eikelenboom
2012-09-04 7:01 ` Keir Fraser
2012-09-04 6:59 ` Keir Fraser
2012-09-04 7:55 ` Jan Beulich
2012-09-04 8:04 ` Keir Fraser
2012-09-04 8:11 ` Keir Fraser
2012-09-04 8:20 ` Sander Eikelenboom
2012-09-04 8:38 ` Jan Beulich
2012-09-04 8:54 ` Keir Fraser
2012-09-04 9:40 ` Jan Beulich
2012-09-04 13:29 ` Andrew Cooper
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