On 10/28/2010 01:54 PM, Ian Molton wrote: >> Well, I like to review an implementation against a spec. > > > True, but then all that would prove is that I can write a spec to > match the code. It would also allow us to check that the spec matches the requirements. Those two steps are easier than checking that the code matches the requirements. > The code is proof of concept. the kernel bit is pretty simple, but I'd > like to get some idea of whether the rest of the code will be accepted > given that theres not much point in having any one (or two) of these > components exist without the other. I guess some graphics people need to be involved. > >> Better, but still unsatisfying. If the server is busy, the caller would >> block. I guess it's expected since it's called from ->fsync(). I'm not >> sure whether that's the best interface, perhaps aio_writev is better. > > The caller is intended to block as the host must perform GL rendering > before allowing the guests process to continue. Why is that? Can't we pipeline the process? > > The only real bottleneck is that processes will block trying to submit > data if another process is performing rendering, but that will only be > solved when the renderer is made multithreaded. The same would happen > on a real GPU if it had only one queue too. > > If you look at the host code, you can see that the data is already > buffered per-process, in a pretty sensible way. if the renderer itself > were made a seperate thread, then this problem magically disappears > (the queuing code on the host is pretty fast). Well, this is out of my area of expertise. I don't like it, but if it's acceptable to the gpu people, okay. > > In testing, the overhead of this was pretty small anyway. Running a > few dozen glxgears and a copy of ioquake3 simultaneously on an intel > video card managed the same framerate with the same CPU utilisation, > both with the old code and the version I just posted. Contention > during rendering just isn't much of an issue. -- error compiling committee.c: too many arguments to function _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
