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Subject: Re: [PATCH] slab.h: Avoid using & for logical and of booleans
From:   William Kucharski <william.kucharski@oracle.com>
In-Reply-To: <20181105131305.574d85469f08a4b76592feb6@linux-foundation.org>
Date:   Tue, 6 Nov 2018 02:45:28 -0700
Cc:     Bart Van Assche <bvanassche@acm.org>, linux-kernel@vger.kernel.org,
        Vlastimil Babka <vbabka@suse.cz>,
        Mel Gorman <mgorman@techsingularity.net>,
        Christoph Lameter <cl@linux.com>, Roman Gushchin <guro@fb.com>,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>, linux-mm@kvack.org
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References: <20181105204000.129023-1-bvanassche@acm.org> <20181105131305.574d85469f08a4b76592feb6@linux-foundation.org>
To:     Andrew Morton <akpm@linux-foundation.org>
Sender: linux-kernel-owner@vger.kernel.org
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> On Nov 5, 2018, at 14:13, Andrew Morton <akpm@linux-foundation.org> wrote:=

>=20
>> On Mon,  5 Nov 2018 12:40:00 -0800 Bart Van Assche <bvanassche@acm.org> w=
rote:
>> -    return type_dma + (is_reclaimable & !is_dma) * KMALLOC_RECLAIM;
>> +    return type_dma + is_reclaimable * !is_dma * KMALLOC_RECLAIM;
>> }
>>=20
>> /*
>=20
> I suppose so.
>=20
> That function seems too clever for its own good :(.  I wonder if these
> branch-avoiding tricks are really worthwhile.

At the very least I'd like to see some comments added as to why that approac=
h was taken for the sake of future maintainers.

William Kucharski