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Message-ID: <1541464370.196084.166.camel@acm.org>
Subject: Re: [PATCH] slab.h: Avoid using & for logical and of booleans
From:   Bart Van Assche <bvanassche@acm.org>
To:     Alexander Duyck <alexander.duyck@gmail.com>
Cc:     linux@rasmusvillemoes.dk,
        Andrew Morton <akpm@linux-foundation.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Vlastimil Babka <vbabka@suse.cz>,
        Mel Gorman <mgorman@techsingularity.net>,
        Christoph Lameter <cl@linux.com>, guro@fb.com,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        linux-mm <linux-mm@kvack.org>
Date:   Mon, 05 Nov 2018 16:32:50 -0800
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On Mon, 2018-11-05 at 16:11 -0800, Alexander Duyck wrote:
+AD4 If we really don't care then why even bother with the switch statement
+AD4 anyway? It seems like you could just do one ternary operator and be
+AD4 done with it. Basically all you need is:
+AD4 return (defined(CONFIG+AF8-ZONE+AF8-DMA) +ACYAJg (flags +ACY +AF8AXw-GFP+AF8-DMA)) ? KMALLOC+AF8-DMA :
+AD4         (flags +ACY +AF8AXw-GFP+AF8-RECLAIMABLE) ? KMALLOC+AF8-RECLAIM : 0+ADs
+AD4 
+AD4 Why bother with all the extra complexity of the switch statement?

I don't think that defined() can be used in a C expression. Hence the
IS+AF8-ENABLED() macro. If you fix that, leave out four superfluous parentheses,
test your patch, post that patch and cc me then I will add my Reviewed-by.

Bart.