On Tue, Jul 7, 2015 at 8:11 PM, C Bergström <cbergst...@pathscale.com> wrote: > On Wed, Jul 8, 2015 at 7:08 AM, Ilia Mirkin <imir...@alum.mit.edu> wrote: >> On Tue, Jul 7, 2015 at 8:07 PM, C Bergström <cbergst...@pathscale.com> wrote: >>> On Wed, Jul 8, 2015 at 6:58 AM, Ben Skeggs <skeg...@gmail.com> wrote: >>>> On 8 July 2015 at 09:53, C Bergström <cbergst...@pathscale.com> wrote: >>>>> regarding >>>>> -------- >>>>> Fixed address allocations weren't going to be part of that, but I see >>>>> that it makes sense for a variety of use cases. One question I have >>>>> here is how this is intended to work where the RM needs to make some >>>>> of these allocations itself (for graphics context mapping, etc), how >>>>> should potential conflicts with user mappings be handled? >>>>> -------- >>>>> As an initial implemetation you can probably assume that the GPU >>>>> offloading is in "exclusive" mode. Basically that the CUDA or OpenACC >>>>> code has full ownership of the card. The Tesla cards don't even have a >>>>> video out on them. To complicate this even more - some offloading code >>>>> has very long running kernels and even worse - may critically depend >>>>> on using the full available GPU ram. (Large matrix sizes and soon big >>>>> Fortran arrays or complex data types) >>>> This doesn't change that, to setup the graphics engine, the driver >>>> needs to map various system-use data structures into the channel's >>>> address space *somewhere* :) >>> >>> I'm not sure I follow exactly what you mean, but I think the answer is >>> - don't setup the graphics engine if you're in "compute" mode. Doing >>> that, iiuc, will at least provide a start to support for compute. >>> Anyone who argues that graphics+compute is critical to have working at >>> the same time is probably a 1%. >> >> On NVIDIA GPUs, compute _is_ part of the graphics engine... aka PGRAPH. > > You can afaik setup PGRAPH without mapping memory for graphics. You > just init the engine and get out of the way.
But... you need to map memory to set up the engine. Not a lot, but it's gotta go *somewhere*. _______________________________________________ Nouveau mailing list Nouveau@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/nouveau