Re: NetBSD block vs raw disk I/O

[Sad Clouds <cryintothebluesky%gmail.com@localhost>]

On Sat, 11 Aug 2018 14:12:02 +0200
Jaromír Doleček <jaromir.dolecek%gmail.com@localhost> wrote:

> Right, you were using read directly from block device, which simply
> isn't optimized since there nothing which uses directly the block
> device.
> 
> Better real-world benchmark is to read a file from mounted filesystem,
> this would include the file system and UVM overhead. There this
> ubc_direct should help.
> 
> Jaromir

Hi, so you're saying that with ucb_direct read/write on mounted file
system should also speed things up compared to NetBSD-8? I see terrible
I/O performance with NetBSD running as a VM on a VirtualBox, just
reading/writing regular files is quite slow compared to Linux VMs on
the same hardware. I've never been able to figure out the reasons for
it, maybe Linux has better integration with VirtualBox and better
optimisations.