Re: [Xen-devel] [PATCH] xen/arm: disable cpuidle when linux isrunning as dom0
From: Julien Grall
Date: Thu Jul 18 2013 - 13:21:30 EST
On 17 July 2013 14:28, Stefano Stabellini
<stefano.stabellini@xxxxxxxxxxxxx> wrote:
> On Mon, 15 Jul 2013, Konrad Rzeszutek Wilk wrote:
>> On Mon, Jul 15, 2013 at 03:21:41PM +0100, Julien Grall wrote:
>> > When linux is running as dom0, Xen doesn't show the physical cpu but a
>> > virtual CPU.
>> > On some ARM SOC (for instance the exynos 5250), linux registers callbacks
>> > for cpuidle. When these callbacks are called, they will modify
>> > directly the physical cpu not the virtual one.
>> It can impact the whole board
>> > instead of dom0.
>
> Certainly this is something that should be fixed at the hypervisor level
> too. However I agree that Linux should try to avoid doing that when
> running on Xen.
>
>
>
>> Should you also call disable_cpufreq() ?
>
> Sounds like a good idea.
> Julien, could you add that to this patch?
I have checked with both the Arndale and Versatile Express without any issue.
I will resend this patch with disable_cpufreq().
--
Julien Grall
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/