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Message-ID: <1563750513.2898.4.camel@HansenPartnership.com>
Subject: Re: [PATCH] unaligned: delete 1-byte accessors
From:   James Bottomley <James.Bottomley@HansenPartnership.com>
To:     Alexey Dobriyan <adobriyan@gmail.com>, akpm@linux-foundation.org
Cc:     linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        axboe@kernel.dk, kvalo@codeaurora.org, john.johansen@canonical.com,
        linux-arch@vger.kernel.org
Date:   Mon, 22 Jul 2019 08:08:33 +0900
In-Reply-To: <20190721215253.GA18177@avx2>
References: <20190721215253.GA18177@avx2>
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On Mon, 2019-07-22 at 00:52 +0300, Alexey Dobriyan wrote:
> Each and every 1-byte access is aligned!

The design idea of this is for parsing descriptors.  We simply chunk up
the describing structure using get_unaligned for everything.  The
reason is because a lot of these structures come with reserved areas
which we may make use of later.  If we're using get_unaligned for
everything we can simply change a u8 to a u16 in the structure
absorbing the reserved padding.  With your change now I'd have to chase
down every byte access and replace it with get_unaligned instead of
simply changing the structure.

What's the significant advantage of this change that compensates for
the problems the above causes?

James