lkml.org 
[lkml]   [2018]   [Nov]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2 3/3] slab: use logical instead of bitwise operation in kmalloc_type()
On Fri,  9 Nov 2018 10:35:34 +0100 Johannes Berg <johannes@sipsolutions.net> wrote:

> The operation here really is more logical than bitwise, even if
> due to the setup the bitwise operation works fine. However, this
> causes a complaint from sparse that the operation doesn't really
> make sense due to the not.
>
> Use a logical and instead of bitwise.
>
> In my (somewhat unscientific) test this caused no differences in
> the generated code.
>
> ...
>
> --- 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;
> }
>
> /*

Thanks. There's presently a bit of head-scratching going on over this.
http://lkml.kernel.org/r/20181105204000.129023-1-bvanassche@acm.org -
please feel free to weigh in ;)

\
 
 \ /
  Last update: 2018-11-09 19:54    [W:0.269 / U:0.160 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site