Gnome DMA-BUF Screencasting Now Limited to Intel Drivers Due to Bugs Elsewhere
Forward of tagging Deliver 3.38 for this week’s GNOME 3.38 desktop open there change into as soon as a closing-minute swap across the DMA-BUF screencasting function.
Earlier this twelve months GNOME builders wired up DMA-BUF screencasting enhance for GNOME on Wayland. With making divulge of DMA-BUF for buffer sharing to steer clear of extra image copies between CPU and GPU reminiscence, the screencasting performance is worthy more efficient. GNOME screencasting is exclusively 1 of many initiatives making divulge of this zero-copy buffer sharing enhance.
But now for the 3.38.0 open, the DMA-BUF screencasting code is determined to most realistic work if the Intel i915 DRM kernel driver is at play. Resulting from other GPU drivers reportedly having buggy DMA-BUF handling, the builders are most realistic cushty for now enabling it for Intel with their effectively-examined DMA-BUF code path.
The swap by Red Hat’s Jonas Ådahl commented, “Appears to be like DMA buffer based exclusively interprocess buffer sharing is more broken than no longer, so for now most realistic enable it when the usage of the i915 driver. For instance vmwgfx, qxl and radeon, it outcomes in mmap() failing to mmap the reminiscence predicament. Varied drivers, e.g. amdgpu will function, nonetheless would possibly possibly possibly hit very slack reminiscence receive paths, leading to worse performance.”
Optimistically the AMDGPU driver and other DRM drivers can receive their DMA-BUF buffer sharing code improved upon in short present.