Re: Unexpected splice "always copy" behavior observed

Christoph Lameter
2010-05-18T15:58:26Z

On Wed, 19 May 2010, Nick Piggin wrote:

> What would be needed is to have filesystem maintainers go through and
> enable it on a case by case basis. It's trivial for tmpfs/ramfs type
> filesystems and I have a patch for those, but I never posted it on.yet.
> Even basic buffer head filesystems IIRC get a little more complex --
> but we may get some milage just out of invalidating the existing
> pagecache rather than getting fancy and trying to move buffers over
> to the new page.

There is a "migration" address space operation for moving pages. Page
migration requires that in order to be able to move dirty pages. Can
splice use that?