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Message-ID: <b3ed3da7-ffa3-0d35-34c1-27b159af43bb@redhat.com>
Date:   Thu, 28 Sep 2023 18:57:18 +0200
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Subject: Re: [PATCH 00/10] Fix confusion around MAX_ORDER
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To:     Mikulas Patocka <mpatocka@redhat.com>
Cc:     "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Mel Gorman <mgorman@suse.de>, Vlastimil Babka <vbabka@suse.cz>,
        David Hildenbrand <david@redhat.com>, quic_jhugo@quicinc.com,
        snitzer@kernel.org, dm <dm-devel@redhat.com>, linux-mm@kvack.org,
        linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org
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 <86e7f97a-ac6b-873d-93b2-1121a464989a@redhat.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
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On 9/28/23 09:50, Mikulas Patocka wrote:
>>> Fix the bugs and then change the definition of MAX_ORDER to be
>>> inclusive: the range of orders user can ask from buddy allocator is
>>> 0..MAX_ORDER now.
> I think that exclusive MAX_ORDER is more intuitive in the C language -
> i.e. if you write "for (i = 0; i < MAX_ORDER; i++)", you are supposed to
> loop over all allowed values. If you declare an array "void
> *array[MAX_ORDER];" you are supposed to hold a value for each allowed
> order.
> 
> Pascal has for loops and array dimensions with inclusive ranges - and it
> is more prone to off-by-one errors.

I agree it's somewhat confusing either way but the ship has sailed, the 
patch has been included in Linux for several months.

Paolo