Re: Memory ordering

On 11/15/2024 11:37 PM, Anton Ertl wrote:

"Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> writes:

On 11/15/2024 9:27 AM, Anton Ertl wrote:

jseigh <jseigh_es00@xemaps.com> writes:

Anybody doing that sort of programming, i.e. lock-free or distributed
algorithms, who can't handle weakly consistent memory models, shouldn't
be doing that sort of programming in the first place.
>
Strongly consistent memory won't help incompetence.

>
Strong words to hide lack of arguments?

>
For instance, a 100% sequential memory order won't help you with, say,
solving ABA.

 
Sure, not all problems are solved by sequential consistency, and yes,
it won't solve race conditions like the ABA problem.  But jseigh
implied that finding it easier to write correct and efficient code for
sequential consistency than for a weakly-consistent memory model
(e.g., Alphas memory model) is incompetent.

>
What if you had to write code for a weakly ordered system, and the
performance guidelines said to only use a membar when you absolutely
have to. If you say something akin to "I do everything using
std::memory_order_seq_cst", well, that is a violation right off the bat.
>
Fair enough?