Re: [PATCH] slab: fix 'dubious: x & !y' warning from Sparse

From: Christopher Lameter
Date: Fri Nov 16 2018 - 08:51:22 EST


On Fri, 16 Nov 2018, Masahiro Yamada wrote:

> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index 918f374..d395c73 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -329,7 +329,7 @@ static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags)
> * If an allocation is both __GFP_DMA and __GFP_RECLAIMABLE, return
> * KMALLOC_DMA and effectively ignore __GFP_RECLAIMABLE
> */
> - return type_dma + (is_reclaimable & !is_dma) * KMALLOC_RECLAIM;
> + return type_dma + (is_reclaimable && !is_dma) * KMALLOC_RECLAIM;
> }

Ok then lets revert the initial patch whose point was to avoid a branch.
&& causes a branch again.