[Intel-gfx] [PATCH 9/9] drm/i915: add bufferless execbuf ioctl

[Chris Wilson]

On Fri, Sep 04, 2015 at 09:59:03AM -0700, Jesse Barnes wrote:
> We just need to pass in an address to execute and some flags, since we
> don't have to worry about buffer relocation or any of the other usual
> stuff.  Returns a fence to be used for synchronization.

There is no need for a flush+fence as part of the execbuf except for
when the client requests one (having it optional in the flags as a
syscall convenience). Just allow the client to inject fences
when it wants and even then it may just elect to do all fencing itself
from userspace. Kernel fencing is only interesting for interclient
operation.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre