[PATCH 2/2] gta02-drm-defconfig: enable FCSE and PREEMPT

[Gilles Chanteperdrix]

On Wed, Sep 01, 2010 at 05:00:28PM +0200, Martix wrote:
> Enables FCSE and PREEMPT to make low-latency system.
> 
> 0002-gta02-drm-defconfig-enable-FCSE-and-PREEMPT.patch
> 
> Sending as attachment to prevent line wrapping.

> Enables FCSE and PREEMPT to make low-latency system.
> 
> Signed-off-by: Martin Holec <martix.cz at gmail.com>
> ---
>  arch/arm/configs/gta02_drm_defconfig |   16 ++++++++++++----
>  1 files changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm/configs/gta02_drm_defconfig b/arch/arm/configs/gta02_drm_defconfig
> index 39a933c..97bc636 100644
> --- a/arch/arm/configs/gta02_drm_defconfig
> +++ b/arch/arm/configs/gta02_drm_defconfig
> @@ -1,7 +1,7 @@
>  #
>  # Automatically generated make config: don't edit
> -# Linux kernel version: 2.6.32.16
> -# Wed Jul 21 13:53:15 2010
> +# Linux kernel version: 2.6.32.21
> +# Wed Sep  1 16:43:37 2010
>  #
>  CONFIG_ARM=y
>  CONFIG_HAVE_PWM=y
> @@ -30,6 +30,7 @@ CONFIG_CONSTRUCTORS=y
>  #
>  CONFIG_EXPERIMENTAL=y
>  CONFIG_BROKEN_ON_SMP=y
> +CONFIG_LOCK_KERNEL=y
>  CONFIG_INIT_ENV_ARG_LIMIT=32
>  CONFIG_LOCALVERSION=""
>  # CONFIG_LOCALVERSION_AUTO is not set
> @@ -292,6 +293,13 @@ CONFIG_ARM_THUMB=y
>  # CONFIG_CPU_DCACHE_DISABLE is not set
>  # CONFIG_CPU_DCACHE_WRITETHROUGH is not set
>  CONFIG_ARM_L1_CACHE_SHIFT=5
> +CONFIG_ARM_FCSE=y
> +# CONFIG_ARM_FCSE_GUARANTEED is not set
> +CONFIG_ARM_FCSE_BEST_EFFORT=y
> +# CONFIG_ARM_FCSE_DYNPID is not set
> +CONFIG_ARM_FCSE_PREEMPT_FLUSH=y
> +# CONFIG_ARM_FCSE_MESSAGES is not set
> +# CONFIG_ARM_FCSE_DEBUG is not set

It is not my business, but since I am CC'ed, I dare.
You should probably enable FCSE_MESSAGES, as they may help you find 
issues caused by the FCSE patch (such as stack size limitaions).

For performances issues, I would rather disable PREEMPT_FLUSH
for lowest overhead (after all, caches flushes take less than 200 us, so 
this should not be a humanly noticeable delay)

I would also test the DYNPID options with the applications you use.

-- 
					    Gilles.