[Openicc] GSoC & oyranos

[Bob Friesenhahn]

On Wed, 1 Apr 2009, Cyrille Berger wrote:

> On Tuesday 31 March 2009, Bob Friesenhahn wrote:
>> If only trivial "exclusive use" is supported (i.e. only user owning
>> the "console" may use the GPU) then a huge number of potential
>> applications are blocked from taking advantage of the GPU and OpenCL
>> becomes a hinderance rather than a clear path forward.
> That's the main advantage of OpenCL over GLSL, they were also designed to be
> used on CPU(s), when you ask the library/driver to run an OpenCL kernel, you
> are not supposed to know if it will be executed on CPU(s) or on GPU, it's the
> library/driver which "decide" what would be the fastest solution (or
> possible). In other word, the scheduling is the job of the driver. As well as
> is security.

Yes, I understand that.  For some reason I have doubts that the 
performance when using OpenCL to execute on the native CPU (as a 
fall-back) will be up to snuff as compared with code which is 
carefully optimized to execute on the native CPU.  If OpenCL is 
optimized for certain CPUs, then other CPU types will suffer as a 
result.

Regardless, there are server (or diminished privilege) execution modes 
which should certainly benefit from use of a GPU if the execution 
model could safely support it.  Quite often the originator of the 
request is not fully trusted or is not trusted at all.  I think that 
it is safe to say that these execution modes are almost as common as 
the dedicated-user modes, even on "single user" type systems.

Examples would be printing system drivers, web-based photo albums like 
"Gallery", or large image posting sites like Flickr.  All of these 
applications may benefit from color management.

OpenCL is currently being pushed by vendors interested in promoting 
their proprietary hardware and proprietary systems.  I am unable to 
find an open-source OpenCL implementation or any actual project to 
produce an open-sourced free OpenCL implementation.  It took ten years 
for OpenMP to finally be supported by GCC.  In the time it takes for 
OpenCL to be independently implemented so that it can be used in Linux 
and *BSD the CPU vendors may very well have integrated GPU 
capabilities, with full compiler support.

Bob
--
Bob Friesenhahn
bfriesen at simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/