ww-mutex: clarify help text for DEBUG_WW_MUTEX_SLOWPATH
diff mbox

Message ID 1409152766-31320-1-git-send-email-robdclark@gmail.com
State New, archived
Headers show

Commit Message

Rob Clark Aug. 27, 2014, 3:19 p.m. UTC
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(+)

Comments

Maarten Lankhorst Aug. 27, 2014, 3:27 p.m. UTC | #1
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"
>

Patch
diff mbox

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"