Re: aio/README.md comments

On Sat, 2025-08-30 at 12:20 -0400, Andres Freund wrote:
> There might be some regressions that make io_method=sync beneficial,
> but short
> to medium term, the goal ought to be to make all non-ridiculous
> configurations
> (I don't care about AIO performing well with s_b=16) to not regress
> meaningfully and for most things to be the same or better with AIO.
>
> I don't see any reason for io_method=sync to be something we should
> have for
> anything other than debugging medium to long term.
>
> Why do you think different?

I don't disagree, but:

(a) It seems inconsistent that the user-facing documentation offers the
"sync" option with no mention that it's a debugging/developer option,
but our internal README says it's only there for debugging.

(b) When AIO gets used for more purposes (e.g. writes), the overall
picture may get more complicated. While I expect the performance to be
much better overall, I wouldn't be surprised if "sync" ends up still
being useful for some purposes.

Regards,
Jeff Davis