Re: [PATCHv2 02/10] kernel: Provide READ_ONCE and ASSIGN_ONCE

[Linus Torvalds]

On Tue, Nov 25, 2014 at 7:59 AM, Paul E. McKenney
<paulmck@xxxxxxxxxxxxxxxxxx> wrote:
>
> We really need something like this to catch invalid sizes:
>
>         default: invoke_nonexistent_function();

Actually, I wonder if we should make the default: case actually just
do something like

   barrier();
   memcpy(res, p, size);
   barrier();

which in no way guarantees that it's an _atomic_ access, but it does
guarantee the semantics that you get one particular value and it won't
get reloaded later..

That would solve the crazy sparc pte issue too.


               Linus
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