Best default for AIO for 4.0?

[Jeremy Allison]

On Tue, Jun 05, 2012 at 11:01:20PM +1000, Andrew Bartlett wrote:
> In waf, AIO is enabled if detected.  In autoconf it must be specified
> with --with-aio-support.
> 
> This is one of the few remaining differences between the builds, so I
> just wanted to check.  Is the AIO code worth enabling by default?

Yes, absolutely.

> I certainly had trouble (dodgy libc) when I last looked at it, and I
> know there are performance challenges.  Can someone remind me what the
> current state of the art is here?

We have fork based and pthread based versions which give significant
benefit. Enable the tests by default (IMHO).

Jeremy.