I have an idea. If all rendering is done on the Nvidia GPU and all the display frame display is done on the Intel GPU, is it possible to force the intel GPU to wait long enough and store the buffer, then synchronize the frames before displaying it on the screen via intel’s TearFree solution in conjunction with nvidia-prime? or DMA-BUF cross-buffer synchronization is already worked on for proper Nvidia Optimus GPU switching using the official Nvidia drivers?
From intel kernel interface manual
Option “TearFree” “boolean”
Disable or enable TearFree updates. This option forces X to perform all rendering to a backbuffer prior to updating the actual display. It requires an extra memory allocation the same size as a framebuffer, the occasional extra copy, and requires Damage tracking. Thus enabling TearFree requires more memory and is slower (reduced throughput) and introduces a small amount of output latency, but it should not impact input latency. However, the update to the screen is then performed synchronously with the vertical refresh of the display so that the entire update is completed before the display starts its refresh. That is only one frame is ever visible, preventing an unsightly tear between two visible and differing frames. Note that this replicates what the compositing manager should be doing, however TearFree will redirect the compositor updates (and those of fullscreen games) directly on to the scanout thus incurring no additional overhead in the composited case. Also note that not all compositing managers prevent tearing, and if the outputs are rotated, there will still be tearing without TearFree enabled.
Thank you. And sorry to bother you.