Only passes that run are measured. The first passes of a race can all run in
a transient (a busy host, code run for the first time): in earlier Grand
Prix runs the three warm-up passes measured 13-15 ms against a steady 3-7 ms
at the same setting. An estimate that high prices most plans out, no pass
runs to correct it, and a plugin that crossfades while passes are shed (R4
Frame Rate) stayed on the crossfade for most or all of the run: 4, 9 and 29
passes in 22 s at 300 Hz, 7 in a verify run at 120 Hz, against about 1400
when the first passes were fast.
render_pass_cost_note_plan() (render_pass_plan.c) counts the plans that
wanted passes since the last measured pass. After 30 (about a second of a
30 Hz game) the warm-up restarts, so plans ask for one pass until three have
been measured again. When the new median is more than 3/4 of the old
estimate, the old one was right (a size that is truly too expensive, or a
host at its limit) and the next wait doubles, up to 960 plans, so these
one-pass warm-ups stay rare; a re-measure that finds the estimate stale
keeps the wait at 30. render_pass_stats reports cost_rewarms.
render_pass_plan_test covers the restart after 30 plans, an estimate that
passes keep measuring never restarting, the minimum wait after a stale
estimate, and the doubling waits when re-measures confirm the estimate
(47 ms at 4K, 10 ms re-measured as 9); render_pass_guards pins the planner's
call and its one-pass re-plan.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Shokunin
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