upstream-submissions/kwin-fourier: validation findings + revised MR body
Captured stock kwin 6.6.4 ioctl baselines on ohm (PineTab2 / RK3566
/ mainline 6.19.10 / Plasma 6.6.4 Wayland):
- Brave + bbb 1080p30 (sw decode), 60 s: 96,120 ioctls, 0 EXPORT_SYNC_FILE
- chromium-fourier + bbb 1080p30, 30 s: 29,128 ioctls, 0 EXPORT_SYNC_FILE,
~7,800 SYNCOBJ_* (explicit sync)
Finding: KWin 6.6.4 + drm-syncobj-aware clients negotiate
wp_linux_drm_syncobj_v1 explicit sync, leaving Transaction::watchDmaBuf
on the legacy implicit-sync path that fires only for clients that
don't advertise drm-syncobj support.
Updated kde-mr-body.md to reflect honest scope: structural cleanup
of the legacy path (still relevant for older clients / V4L2 pipelines
that don't wrap dmabufs in syncobjs) rather than the originally-
hypothesized per-frame ioctl reduction. Patch is correct by
construction; no regression on the no-targeted-path workload.
Evidence files saved under measurements/.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
test0r
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