AIO in 10.0-RELEASE

[Jan Bramkamp]

On 07/04/16 19:45, Rick Miller wrote:
> Please reply directly as I am not currently subscribed to this particular
> mailing list...
>
> A user has been implementing AIO features in an application on FreeBSD
> 10.0-RELEASE.  They assert that, despite aio(4) stating that it is enabled
> either statically (with VFS_AIO in the kernel config) or dynamically
> (kldload), in their development environment there was no requirement for
> either of these methods of enabling AIO.  My google-foo is failing me when
> it comes to FreeBSD's AIO.
>
> This question defies logic, but is it possible that AIO works by default in
> earlier versions of 10.0 and not in more recent version of 10.0 without any
> local system changes?
>
> It is understood that AIO has recently been enabled by default in FreeBSD
> 10.3 and -CURRENT.  This particular scenario is applicable to 10.0.
>

IIRC FreeBSD 10.0 - 10.2 don't include AIO support in their GENERIC 
kernel configurations and you have to either load ther aio.ko kernel 
module or configure, build and install a kernel with static AIO support 
to use AIO on FreeBSD 10.0 - 10.2.

Run `kldstat -v | grep aio` to check if your running kernel (+ modules) 
includes AIO support.