lkml.org 
[lkml]   [2018]   [Nov]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] slab.h: Avoid using & for logical and of booleans
On Mon 2018-11-05 12:40:00, Bart Van Assche wrote:
> This patch suppresses the following sparse warning:
>
> ./include/linux/slab.h:332:43: warning: dubious: x & !y
>
> Fixes: 1291523f2c1d ("mm, slab/slub: introduce kmalloc-reclaimable caches")
> Cc: Vlastimil Babka <vbabka@suse.cz>
> Cc: Mel Gorman <mgorman@techsingularity.net>
> Cc: Christoph Lameter <cl@linux.com>
> Cc: Roman Gushchin <guro@fb.com>
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
> include/linux/slab.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index 918f374e7156..97d0599ddb7b 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;
> }
>

What is wrong with && ? If logical and is better done by multiply,
that's compiler job, and compiler should be fixed to do it...


Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2018-11-19 12:05    [W:0.118 / U:3.092 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site