KDE merge-request body for kwin-fourier patch 0002 (the
upstream-shape, not the diagnostic 0001 bypass).
Captures:
- Summary of the change (poll dmabuf fd directly, drop the
EXPORT_SYNC_FILE+sync_file roundtrip).
- Why it matters (per-frame ioctl overhead on Mali hardware,
measurable contributor to compositor latency spikes).
- Side effects (drop unused linux/dma-buf.h and xf86drm.h
includes, remove exportWaitSyncFile static helper).
- Alternative considered (16ms timeout — preserves shape but
doesn't remove the syscalls; rejected for that reason).
- Validation context on PineTab2.
- Future work pointer at the kernel-side dma_resv work.
- KDE contribution flow boilerplate: account, SSH, fork+branch
recipe, reviewer suggestions (vladz, zamundaaa, David Edmundson),
labels (Component::Wayland, Performance, Backport).
Validation gate before submitting: build kwin-fourier with 0002
instead of 0001, install on ohm, confirm equivalence with the
0001-validated playback. Strace numbers for the syscall reduction
go into the MR body once captured.
This is a parallel to the qt6 submission draft committed earlier.
marfrit
92b9c91bd3