From: Joanna Rutkowska <joanna@invisiblethingslab.com>
To: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: xen-devel@lists.xensource.com,
Rafal Wojtczuk <rafal@invisiblethingslab.com>
Subject: Re: dom0 is stalled until a keypress
Date: Tue, 06 Sep 2011 18:35:58 +0200 [thread overview]
Message-ID: <4E664BEE.9000208@invisiblethingslab.com> (raw)
In-Reply-To: <36a5b662-4420-41aa-be01-445f83b15a7b@default>
[-- Attachment #1.1: Type: text/plain, Size: 1625 bytes --]
On 09/06/11 17:49, Dan Magenheimer wrote:
>> From: Rafal Wojtczuk [mailto:rafal@invisiblethingslab.com]
>> Sent: Monday, September 05, 2011 3:20 AM
>> To: xen-devel@lists.xensource.com
>> Subject: [Xen-devel] dom0 is stalled until a keypress
>>
>> Hello,
>> The following bizarre behaviour was observed on xen4.1+suse dom0 2.6.38, on
>> an old Core Duo laptop; maybe someone can hint what is wrong.
>> Dom0 boot stalls after an init.d script prints "Starting udev". Then nothing
>> seems to happen. I need to press any key to observe progress - I need to do
>> it tens of times for the boot to finish. After X starts fine, then there is
>> no need for keypressing anymore.
>> A particularly disturbing fact is that qrexec_daemon parent, that basically
>> does
>> for (;;) { sleep(1); fprintf(stderr, "."); }
>> does not print dots, until a keypress arrives. So something is very wrong
>> with timers.
>> Somehow similarly, pm-suspend sometimes hangs at some stage - after detaching
>> power cord, machine enters S3 immediately.
>> This is vaguely similar to the issue described in
>> https://lkml.org/lkml/2008/9/14/122
>> but this time, "nohz=off" does not help.
>>
>> "cpufreq=dom0-kernel" cures the symptoms; but it is not a sideeffectless
>> solution. Any idea what is going on or how to debug it ?
>
> ISTR seeing this on a Core(2?)Duo laptop and I think the
> workaround was setting max_cstate=0 (as Xen boot parameter).
>
But what was the actual problem? Setting max_cstate is probably even
worse for power management than setting cpufreq=dom-kernel, isn't it?
Thanks,
joanna.
[-- Attachment #1.2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 518 bytes --]
[-- Attachment #2: Type: text/plain, Size: 138 bytes --]
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel
next prev parent reply other threads:[~2011-09-06 16:35 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-05 9:19 dom0 is stalled until a keypress Rafal Wojtczuk
2011-09-06 15:49 ` Dan Magenheimer
2011-09-06 16:35 ` Joanna Rutkowska [this message]
2011-09-06 17:17 ` Dan Magenheimer
2011-09-07 9:03 ` Joanna Rutkowska
2011-09-07 9:35 ` Jan Beulich
2011-09-07 13:29 ` Rafal Wojtczuk
2011-09-06 19:04 ` Jeremy Fitzhardinge
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4E664BEE.9000208@invisiblethingslab.com \
--to=joanna@invisiblethingslab.com \
--cc=dan.magenheimer@oracle.com \
--cc=rafal@invisiblethingslab.com \
--cc=xen-devel@lists.xensource.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).