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* [PATCH] ww-mutex: clarify help text for DEBUG_WW_MUTEX_SLOWPATH
@ 2014-08-27 15:19 Rob Clark
  2014-08-27 15:27 ` Maarten Lankhorst
  0 siblings, 1 reply; 2+ messages in thread
From: Rob Clark @ 2014-08-27 15:19 UTC (permalink / raw)
  To: linux-kernel; +Cc: maarten.lankhorst, Daniel Vetter, dri-devel, Rob Clark

We really don't want distro's enabling this in their kernels.  Try and
make that more clear.

Signed-off-by: Rob Clark <robdclark@gmail.com>
---
 lib/Kconfig.debug | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 07c2832..1b233fc 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -892,6 +892,10 @@ config DEBUG_WW_MUTEX_SLOWPATH
 	 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
 	 will test all possible w/w mutex interface abuse with the
 	 exception of simply not acquiring all the required locks.
+	 Note that this feature can introduce significant overhead, so
+	 it really should not be enabled in a production or distro kernel,
+	 even a debug kernel.  If you are a driver writer, enable it.  If
+	 you are a distro, do not.
 
 config DEBUG_LOCK_ALLOC
 	bool "Lock debugging: detect incorrect freeing of live locks"
-- 
1.9.3


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] ww-mutex: clarify help text for DEBUG_WW_MUTEX_SLOWPATH
  2014-08-27 15:19 [PATCH] ww-mutex: clarify help text for DEBUG_WW_MUTEX_SLOWPATH Rob Clark
@ 2014-08-27 15:27 ` Maarten Lankhorst
  0 siblings, 0 replies; 2+ messages in thread
From: Maarten Lankhorst @ 2014-08-27 15:27 UTC (permalink / raw)
  To: Rob Clark, linux-kernel; +Cc: Daniel Vetter, dri-devel

Acked-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>

On 27-08-14 17:19, Rob Clark wrote:
> We really don't want distro's enabling this in their kernels.  Try and
> make that more clear.
> 
> Signed-off-by: Rob Clark <robdclark@gmail.com>
> ---
>  lib/Kconfig.debug | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 07c2832..1b233fc 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -892,6 +892,10 @@ config DEBUG_WW_MUTEX_SLOWPATH
>  	 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
>  	 will test all possible w/w mutex interface abuse with the
>  	 exception of simply not acquiring all the required locks.
> +	 Note that this feature can introduce significant overhead, so
> +	 it really should not be enabled in a production or distro kernel,
> +	 even a debug kernel.  If you are a driver writer, enable it.  If
> +	 you are a distro, do not.
>  
>  config DEBUG_LOCK_ALLOC
>  	bool "Lock debugging: detect incorrect freeing of live locks"
> 

^ permalink raw reply	[flat|nested] 2+ messages in thread

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