Re: Compilers and RCU readers: Once more unto the breach!

From: Paul E. McKenney
Date: Fri May 22 2015 - 09:13:06 EST


On Fri, May 22, 2015 at 08:43:44AM +0200, Ingo Molnar wrote:
>
> * Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> > (a) the "official" rules are completely pointless, and make sense
> > only because the standard is written for some random "abstract
> > machine" that doesn't actually exist.
>
> Presuming the intent of the abstract machine specification is to avoid
> being seen as biased towards any specific machine (politics), maybe
> write this as:
>
> (a) the "official" rules are written for a somewhat weird and
> complex "union of all known and theoretically possible CPU
> architectures that exist or which might exist in the future",
> which machine does not actually exist in practice, but which
> allows a single abstract set of rules to apply to all machines.
> These rules are complex, but if applied to a specific machine
> they become considerably simpler. Here's a few examples: ...
>
> ?
>
> (Assuming it's a goal of this standard to be human parseable to more
> than a few dozen people on the planet.)

Should something based on Section 7.9 go in, then I would need to add
a more developer-friendly explanation in Documentation/RCU, no two
ways about it! ;-)

Thanx, Paul

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