On Sat, Dec 05, 2015 at 11:12:08AM +0100, Daniel Vetter wrote: > Given that I think the current etnaviv is a sound architecture. And I'm > not saying that because drm requires everything to be smashed into one > driver, since that's simple not the case. There's other reasons as well, mostly from the performance point of view. Having separate DRM devices for each GPU means you need to use dmabuf to share buffers across the GPUs. This brings with it several kinds of overhead: 1. having more fd usage in the client programs. 2. having more memory usage as a result. 3. having more locks, due to more object lists. 4. having the overhead from the DMA API when importing buffers between different GPU nodes. >From my performance measurements over the last month, the top hit is currently from the DMA API, so having to export and import buffers between different GPU devices is just going to make that worse. -- FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
