Re: [patch 2/4] kref debugging config option

[Greg KH <greg@kroah.com>]

On Mon, Apr 24, 2006 at 04:33:35PM +0800, Akinobu Mita wrote:
> This patch converts all WARN_ON() in kref code to BUG_ON().
> And split them into new DEBUG_KREF config option.
> 
> Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
> 
>  lib/Kconfig.debug |    7 +++++++
>  lib/kref.c        |   30 +++++++++++++++++++++++++-----
>  2 files changed, 32 insertions(+), 5 deletions(-)
> 
> Index: 2.6-git/lib/Kconfig.debug
> ===================================================================
> --- 2.6-git.orig/lib/Kconfig.debug
> +++ 2.6-git/lib/Kconfig.debug
> @@ -130,6 +130,13 @@ config DEBUG_KOBJECT
>  	  If you say Y here, some extra kobject debugging messages will be sent
>  	  to the syslog. 
>  
> +config DEBUG_KREF
> +	bool "kref debugging"
> +	depends on DEBUG_KERNEL
> +	help
> +	  This option enables addition error checking for kref,
> +	  library routines for handling generic reference counted objects.
> +
>  config DEBUG_HIGHMEM
>  	bool "Highmem debugging"
>  	depends on DEBUG_KERNEL && HIGHMEM
> Index: 2.6-git/lib/kref.c
> ===================================================================
> --- 2.6-git.orig/lib/kref.c
> +++ 2.6-git/lib/kref.c
> @@ -20,16 +20,38 @@
>   */
>  void kref_init(struct kref *kref)
>  {
> -	atomic_set(&kref->refcount,1);
> +	atomic_set(&kref->refcount, 1);
>  }
>  
> +#ifdef CONFIG_DEBUG_KREF
> +static void kref_get_debug_check(struct kref *kref)
> +{
> +	BUG_ON(!atomic_read(&kref->refcount));
> +}

Eeek, no, you do not want to do this.  Unless you never want to get a
bug report with this enabled :)

thanks,

greg k-h