Performance profiling that can say no
Instrumentation is most valuable when it can kill the optimization you wanted to build.
Current explanation
Log gaps and aggregate profiles can charge time to the wrong owner. A stronger investigation measures the actual seam, replays the target path, and separates direct component savings from whole-launch critical-path movement. If the measured benefit is small or weakens correctness, the right result can be not shipping the optimization.
Lesson path
- 01
State the theory
currentName the presumed owner and predicted timing.
- 02
Measure the seam
nextSeparate entry-to-exit from time between calls.
- 03
Decide
nextKeep, move, or reject the optimization using the measured boundary.
Open questions
- How do direct savings fail to move the critical path?
Selected Q&A
Is a 65ms rejection a failed investigation?
No. It protected stronger content detection and redirected effort away from a weak trade.
Next actions
- Write a discriminator for one current performance theory.
Sources
- Preflight evidence packet #322
Current profiles, experiments, and performance evidence.
Revision trail
· learning:performance-profiling-that-can-say-no@r1
Collected queue, graphics, path, and digest reversals into one method.