Re: [Outreachy kernel] [PATCH] Staging: lustre: interval_tree: Convert inline function to macro

[Greg KH <gregkh@linuxfoundation.org>]

On Sun, Nov 01, 2015 at 12:15:44AM +0530, Shivani Bhardwaj wrote:
> Convert the function max_u64() to macro because macros tend to be more
> flexible than inline functions and here, the macro is going to be type
> safe so there are not going to be any side effects.
> 
> Signed-off-by: Shivani Bhardwaj <shivanib134@gmail.com>
> ---
>  drivers/staging/lustre/lustre/ldlm/interval_tree.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/staging/lustre/lustre/ldlm/interval_tree.c b/drivers/staging/lustre/lustre/ldlm/interval_tree.c
> index a2ea8e5..52d0afd 100644
> --- a/drivers/staging/lustre/lustre/ldlm/interval_tree.c
> +++ b/drivers/staging/lustre/lustre/ldlm/interval_tree.c
> @@ -42,6 +42,8 @@
>  #include "../include/obd_support.h"
>  #include "../include/interval_tree.h"
>  
> +#define max_u64(x, y) ((x > y) ? x : y)

Ick, no, there is already a _correct_ macro in the kernel for this,
don't try to create another one that does not work properly for all
users.

And your patch is also backwards, inline functions are better than
macros, don't ever convert from an inline function to a macro.

thanks,

greg k-h