)]}'
{
  "commit": "b2ac0e7a9089039e62b84d246eca83f84c540f76",
  "tree": "babd158db382b570a612672406fe87779066c577",
  "parents": [
    "c91f7e86727683118b6096757717135463fdcdd7"
  ],
  "author": {
    "name": "Takuto Ikuta",
    "email": "tikuta@google.com",
    "time": "Tue Mar 24 17:01:53 2026 +0900"
  },
  "committer": {
    "name": "GN LUCI",
    "email": "gn-scoped@luci-project-accounts.iam.gserviceaccount.com",
    "time": "Tue Mar 24 04:08:33 2026 -0700"
  },
  "message": "Limit the maximum number of GN worker threads to 32.\n\nOn machines with high core counts (e.g., 128 cores), using all available\nCPUs for worker threads significantly slows down `gn gen` due to thread\nscheduling overhead and contention.\n\nThis change caps the default number of worker threads at 32 while\nmaintaining the existing minimum of 8.\n\nProfiling results of `gn gen` for Chrome using hyperfine on a 128-core\nLinux machine:\n\nSummary\n  ./buildtools/linux64/gn gen out/Default/ --threads\u003d32 ran\n    1.01 ± 0.03 times faster than ./buildtools/linux64/gn gen out/Default/ --threads\u003d16\n    1.07 ± 0.03 times faster than ./buildtools/linux64/gn gen out/Default/ --threads\u003d48\n    1.13 ± 0.03 times faster than ./buildtools/linux64/gn gen out/Default/ --threads\u003d64\n    1.26 ± 0.03 times faster than ./buildtools/linux64/gn gen out/Default/ --threads\u003d96\n    1.28 ± 0.04 times faster than ./buildtools/linux64/gn gen out/Default/ --threads\u003d8\n\nThis improved gn gen for android too.\n\nSummary\n  ./buildtools/linux64/gn --threads\u003d32 gen out/android ran\n    1.19 ± 0.04 times faster than ./buildtools/linux64/gn gen out/android\n\nBug: 484863025\nChange-Id: I44b467c1813a32015666926d8bbaaad4206b5447\nReviewed-on: https://gn-review.googlesource.com/c/gn/+/21740\nReviewed-by: David Turner \u003cdigit@google.com\u003e\nCommit-Queue: Takuto Ikuta \u003ctikuta@google.com\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "ac903fa2c0f12af069f2345c0ee4f23cfd6b2269",
      "old_mode": 33188,
      "old_path": "src/util/worker_pool.cc",
      "new_id": "3bff847d475fe30ce0e75b2c20d0422942765958",
      "new_mode": 33188,
      "new_path": "src/util/worker_pool.cc"
    }
  ]
}