perf/hist/ mirrors perf/cf/: a driver that runs each config under nsys,
the traced process, settings and a README. The fill (H2D + fill_bin_major
per frame) and the readout (bin_to_pixel_major + one D2H per values())
are reported separately. Only one chunk of frames is held in host memory
and re-queued until the requested frame count.
gpu_span.analyze() takes an optional engines subset, so the one-off
readout D2H doesn't count towards the fill window or roofline. Default
output is unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
