)]}'
{
  "commit": "f57de24649eb8a06572af5250adb71c9307a821d",
  "tree": "9235be5b5051512e6bb6985131eb0f0e306d2c5a",
  "parents": [
    "d18a2dc0663e4d2643e7a81d22c53118cbdffd67"
  ],
  "author": {
    "name": "Connal de Souza",
    "email": "connaldesouza@google.com",
    "time": "Wed Oct 28 18:36:12 2026 -0700"
  },
  "committer": {
    "name": "Copybara-Service",
    "email": "copybara-worker@google.com",
    "time": "Thu Nov 05 17:59:30 2026 -0800"
  },
  "message": "Size SpinLock and Mutex spin limits to machine capacity.\n\nFixed spin-loop iteration counts spend 2–4× more wall-clock time on slower CPUs than on faster ones. In fleet experiments, longer fixed-iteration spins improved performance on smaller and mid-size machines, but regressed performance on the highest-capacity machines, where packed work scales with machine compute capacity.\n\nCalibrate the spin duration once on first contention inversely proportional to machine compute capacity, estimating per-CPU speed via an integer-latency probe.\n\nPiperOrigin-RevId: 1009321328\n",
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