Re: [PATCH] slab.h: Avoid using & for logical and of booleans

[Vlastimil Babka]

On 11/13/18 7:22 PM, Vlastimil Babka wrote:
> On 11/12/18 10:55 AM, David Laight wrote:
>> From: Vlastimil Babka [mailto:vbabka@xxxxxxx]
>>> Sent: 09 November 2018 19:16
>> ...
>>> This? Not terribly elegant, but I don't see a nicer way right now...
>>
>> Maybe just have two copies of the function body?
>>
>>  static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags)
>> {
>> #ifndef CONFIG_ZONE_DMA
>> 	return flags & __GFP_RECLAIMABLE ? KMALLOC_RECLAIM : KMALLOC_NORMAL;
>> #else
>> 	if (likely((flags & (__GFP_DMA | __GFP_RECLAIMABLE)) == 0))
>> 		return KMALLOC_NORMAL;
>> 	return flags & __GFP_DMA ? KMALLOC_DMA : KMALLOC_RECLAIM;
>> #endif
>> }
> 
> OK that's probably the most straightforward to follow, thanks.
> Note that for CONFIG_ZONE_DMA=n the result is identical to original code and
> all other attempts. flags & __GFP_DMA is converted to 1/0 index without branches
> or cmovs or whatnot.

Ping? Seems like people will report duplicates until the sparse warning
is gone in mainline...

Also CC linux-mm which was somehow lost.


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