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From: konrad.wilk@oracle.com (Konrad Rzeszutek Wilk)
To: linux-arm-kernel@lists.infradead.org
Subject: [Xen-devel] [PATCH] xen/arm: disable cpuidle when linux is running as dom0
Date: Mon, 15 Jul 2013 11:25:32 -0400	[thread overview]
Message-ID: <20130715152532.GC5774@phenom.dumpdata.com> (raw)
In-Reply-To: <1373898101-15633-1-git-send-email-julien.grall@linaro.org>

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.

Should you also call disable_cpufreq() ?

> 
> Signed-off-by: Julien Grall <julien.grall@linaro.org>
> ---
>  arch/arm/xen/enlighten.c |    7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index 49839d8..a98999f 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -24,6 +24,8 @@
>  #include <linux/of.h>
>  #include <linux/of_irq.h>
>  #include <linux/of_address.h>
> +#include <linux/cpuidle.h>
> +#include <linux/cpufreq.h>
>  
>  #include <linux/mm.h>
>  
> @@ -292,6 +294,11 @@ static int __init xen_pm_init(void)
>  {
>  	pm_power_off = xen_power_off;
>  	arm_pm_restart = xen_restart;
> +	/*
> +	 * Making sure board specific code will not set up ops for
> +	 * cpu idle.
> +	 */
> +	disable_cpuidle();
>  
>  	return 0;
>  }
> -- 
> 1.7.10.4
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel at lists.xen.org
> http://lists.xen.org/xen-devel

WARNING: multiple messages have this Message-ID (diff)
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Julien Grall <julien.grall@linaro.org>
Cc: stefano.stabellini@eu.citrix.com, ian.campbell@citrix.com,
	patches@linaro.org, linux-kernel@vger.kernel.org,
	xen-devel@lists.xen.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [Xen-devel] [PATCH] xen/arm: disable cpuidle when linux is running as dom0
Date: Mon, 15 Jul 2013 11:25:32 -0400	[thread overview]
Message-ID: <20130715152532.GC5774@phenom.dumpdata.com> (raw)
In-Reply-To: <1373898101-15633-1-git-send-email-julien.grall@linaro.org>

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.

Should you also call disable_cpufreq() ?

> 
> Signed-off-by: Julien Grall <julien.grall@linaro.org>
> ---
>  arch/arm/xen/enlighten.c |    7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index 49839d8..a98999f 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -24,6 +24,8 @@
>  #include <linux/of.h>
>  #include <linux/of_irq.h>
>  #include <linux/of_address.h>
> +#include <linux/cpuidle.h>
> +#include <linux/cpufreq.h>
>  
>  #include <linux/mm.h>
>  
> @@ -292,6 +294,11 @@ static int __init xen_pm_init(void)
>  {
>  	pm_power_off = xen_power_off;
>  	arm_pm_restart = xen_restart;
> +	/*
> +	 * Making sure board specific code will not set up ops for
> +	 * cpu idle.
> +	 */
> +	disable_cpuidle();
>  
>  	return 0;
>  }
> -- 
> 1.7.10.4
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel

  parent reply	other threads:[~2013-07-15 15:25 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-15 14:21 [PATCH] xen/arm: disable cpuidle when linux is running as dom0 Julien Grall
2013-07-15 14:21 ` Julien Grall
2013-07-15 15:25 ` Konrad Rzeszutek Wilk
2013-07-15 15:25 ` Konrad Rzeszutek Wilk [this message]
2013-07-15 15:25   ` [Xen-devel] " Konrad Rzeszutek Wilk
2013-07-15 16:22   ` Julien Grall
2013-07-15 16:22   ` [Xen-devel] " Julien Grall
2013-07-15 16:22     ` Julien Grall
2013-07-17 13:28   ` Stefano Stabellini
2013-07-17 13:28     ` Stefano Stabellini
2013-07-18 17:20     ` Julien Grall
2013-07-18 17:20       ` Julien Grall
2013-07-18 17:20     ` Julien Grall
2013-07-17 13:28   ` Stefano Stabellini

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