Zero Copy writes for Samba

[Jeremy Allison]

On Wed, Feb 26, 2014 at 09:48:16PM +0000, Kuhn, Steven wrote:
> Hi Jeremy,
> 
> Thank you for your reply.
> 
> I do not know if I have a modified kernel that fixes splice performance.  I have the OpenWrt 3.4.0 distribution.

Then you don't :-).

> What should I look for in the kernel to see if it has the modifications you are referring to?

No distribution has such a modified splice. Some
NAS products have experimented with this, but
no fixes have ever been deemed good or safe
enough to go into the mainline kernel.

> Can you point me to the kernel modifications to add myself?

There aren't any, that's the point :-(.

You're better off without splice. Use the aio_pthread
VFS module instead.