Re: [PATCH/RFC 7/7] kernel: Force ACCESS_ONCE to work only on scalar types

[Linus Torvalds]

On Mon, Nov 24, 2014 at 11:42 AM, Paul E. McKenney
<paulmck@xxxxxxxxxxxxxxxxxx> wrote:
>
> OK, how about the following?

Ugh. Disgusting.

Why the heck isn't it just "sizeof(*__vp) <= sizeof(long)"?

If the architecture has a 3-byte scalar type, then it probably has a
3-byte load.

> It complains if the variable is too large, for example, long long on
> 32-bit systems or large structures.  It is OK loading from and storing
> to small structures as well, which I am having a hard time thinking of
> as a disadvantage.

.. but that's *exactly* the gcc bug in question. It's a word-sized
struct that gcc loads twice.

                          Linus
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