From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Tobias Geiger <tobias.geiger@vido.info>
Cc: xen-devel@lists.xensource.com,
Joanna Rutkowska <joanna@invisiblethingslab.com>
Subject: Re: A clocksource question
Date: Fri, 12 Mar 2010 14:02:38 -0800 [thread overview]
Message-ID: <4B9AB9FE.8070601@goop.org> (raw)
In-Reply-To: <201003122256.02254.tobias.geiger@vido.info>
On 03/12/2010 01:56 PM, Tobias Geiger wrote:
> kbpc2:~# cat
> /sys/devices/system/clocksource/clocksource0/current_clocksource
> xen
> kbpc2:~# cat
> /sys/devices/system/clocksource/clocksource0/available_clocksource
> xen
> kbpc2:~# echo "jiffies"
>
>> /sys/devices/system/clocksource/clocksource0/current_clocksource
>>
> kbpc2:~# dmesg | tail -1
> [ 7898.642404] Override clocksource jiffies is not HRT compatible. Cannot switch
> while in HRT/NOHZ mode
> kbpc2:~#
>
> Seems like it's not possible to switch to jiffies - however:
> kbpc2:~# zcat /proc/config.gz | grep NO_HZ
> # CONFIG_NO_HZ is not set
>
> but CONFIG_SCHED_HRTICK=y
>
Interesting. BTW, does NO_HZ change the behaviour of this? In
principle NO_HZ should be preferable, and particularly in a virtual
machine since it should limit the number of timer interrupts.
Joanna, are you using NO_HZ?
Thanks,
J
next prev parent reply other threads:[~2010-03-12 22:02 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-09 10:47 A clocksource question Joanna Rutkowska
2010-03-09 10:50 ` Keir Fraser
2010-03-09 10:54 ` Joanna Rutkowska
2010-03-09 11:06 ` Joanna Rutkowska
2010-03-09 12:07 ` Pasi Kärkkäinen
2010-03-09 12:10 ` Joanna Rutkowska
2010-03-09 15:42 ` Konrad Rzeszutek Wilk
2010-03-09 23:36 ` Jeremy Fitzhardinge
2010-03-10 22:13 ` Joanna Rutkowska
2010-03-11 0:07 ` Dan Magenheimer
2010-03-11 0:15 ` Joanna Rutkowska
2010-03-11 0:21 ` Ian Pratt
2010-03-11 0:44 ` Dan Magenheimer
2010-03-12 0:34 ` Joanna Rutkowska
2010-03-11 0:52 ` Joanna Rutkowska
2010-03-11 1:06 ` Jeremy Fitzhardinge
2010-03-11 1:19 ` Joanna Rutkowska
2010-03-11 4:55 ` Jeremy Fitzhardinge
2010-03-11 10:49 ` Joanna Rutkowska
2010-03-12 0:27 ` Joanna Rutkowska
2010-03-12 0:49 ` Jeremy Fitzhardinge
2010-03-12 0:38 ` Joanna Rutkowska
2010-03-12 19:02 ` Joanna Rutkowska
2010-03-12 21:24 ` Jeremy Fitzhardinge
2010-03-12 21:56 ` Tobias Geiger
2010-03-12 22:02 ` Jeremy Fitzhardinge [this message]
2010-03-12 21:01 ` Joanna Rutkowska
2010-03-12 21:13 ` Joanna Rutkowska
2010-03-12 23:48 ` Jeremy Fitzhardinge
2010-03-13 9:58 ` Joanna Rutkowska
2010-03-13 19:30 ` Jeremy Fitzhardinge
2010-03-15 6:49 ` Tobias Geiger
2010-03-16 6:01 ` Joanna Rutkowska
2010-03-17 13:35 ` Tobias Geiger
2010-03-17 15:21 ` Joanna Rutkowska
2010-03-17 16:20 ` Jeremy Fitzhardinge
2010-03-17 17:05 ` Joanna Rutkowska
2010-03-17 17:21 ` Jeremy Fitzhardinge
2010-03-17 16:26 ` Dan Magenheimer
2010-03-12 22:56 ` Tobias Geiger
2010-03-11 7:47 ` Keir Fraser
-- strict thread matches above, loose matches on Subject: below --
2010-03-12 11:42 Tobias Geiger
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