perf(generator): fork a process per kind, and don't collect garbage during generation - #1071

[taskcluster 2026-10-14T06:53:51.283Z] Worker Type (mozilla-t/pre-commit) settings:
[taskcluster 2026-10-14T06:53:51.283Z]   {
[taskcluster 2026-10-14T06:53:51.283Z]     "generic-worker": {
[taskcluster 2026-10-14T06:53:51.283Z]       "config": {
[taskcluster 2026-10-14T06:53:51.283Z]         "capacity": 1,
[taskcluster 2026-10-14T06:53:51.283Z]         "headlessTasks": true
[taskcluster 2026-10-14T06:53:51.283Z]       },
[taskcluster 2026-10-14T06:53:51.283Z]       "engine": "multiuser",
[taskcluster 2026-10-14T06:53:51.283Z]       "go-arch": "amd64",
[taskcluster 2026-10-14T06:53:51.283Z]       "go-os": "linux",
[taskcluster 2026-10-14T06:53:51.283Z]       "go-version": "go1.27.1",
[taskcluster 2026-10-14T06:53:51.283Z]       "release": "https://github.com/taskcluster/taskcluster/releases/tag/v110.1.0",
[taskcluster 2026-10-14T06:53:51.283Z]       "revision": "8522ee4ea64acdb407128264f3b3b56a2e24c2d9",
[taskcluster 2026-10-14T06:53:51.283Z]       "source": "https://github.com/taskcluster/taskcluster/commits/8522ee4ea64acdb407128264f3b3b56a2e24c2d9",
[taskcluster 2026-10-14T06:53:51.283Z]       "version": "110.1.0"
[taskcluster 2026-10-14T06:53:51.283Z]     },
[taskcluster 2026-10-14T06:53:51.283Z]     "image": "projects/taskcluster-imaging/global/images/gw-fxci-gcp-l1-2404-amd64-headless-googlecompute-2026-09-30",
[taskcluster 2026-10-14T06:53:51.283Z]     "instance-id": "7394898079928855566",
[taskcluster 2026-10-14T06:53:51.283Z]     "instance-type": "projects/887720501152/machineTypes/c3d-standard-4",
[taskcluster 2026-10-14T06:53:51.283Z]     "local-ipv4": "10.128.0.12",
[taskcluster 2026-10-14T06:53:51.283Z]     "project-id": "fxci-production-level1-workers",
[taskcluster 2026-10-14T06:53:51.283Z]     "public-hostname": "mozilla-t-pre-commit-rsr-k3kfsfegcxnsb92okw.c.fxci-production-level1-workers.internal",
[taskcluster 2026-10-14T06:53:51.283Z]     "public-ipv4": "136.65.73.110",
[taskcluster 2026-10-14T06:53:51.283Z]     "region": "us-central1",
[taskcluster 2026-10-14T06:53:51.283Z]     "zone": "us-central1-c"
[taskcluster 2026-10-14T06:53:51.283Z]   }
[taskcluster 2026-10-14T06:53:51.283Z] Task ID: djD_mCb_QnOFl7zhOcT0UQ
[taskcluster 2026-10-14T06:53:51.283Z] === Task Starting ===
[taskcluster 2026-10-14T06:53:52.307Z] [mounts] Moving existing writable directory cache lint-pre-commit-uv-v1 from /home/generic-worker/caches/GhSW4QmlS8eLo9ckMSO1pQ to /home/task_djD_mCb_QnOFl_0/cache0
[taskcluster 2026-10-14T06:53:52.307Z] [mounts] Creating directory /home/task_djD_mCb_QnOFl_0
[taskcluster 2026-10-14T06:53:52.318Z] [mounts] Successfully mounted writable directory cache '/home/task_djD_mCb_QnOFl_0/cache0'
[taskcluster 2026-10-14T06:53:52.318Z] [mounts] Moving existing writable directory cache lint-pre-commit-repos-v1 from /home/generic-worker/caches/d3lIxFxqSfmcAkumaIq3FQ to /home/task_djD_mCb_QnOFl_0/cache1
[taskcluster 2026-10-14T06:53:52.318Z] [mounts] Creating directory /home/task_djD_mCb_QnOFl_0
[taskcluster 2026-10-14T06:53:52.328Z] [mounts] Successfully mounted writable directory cache '/home/task_djD_mCb_QnOFl_0/cache1'
[taskcluster 2026-10-14T06:53:52.328Z] [mounts] Moving existing writable directory cache lint-pre-commit-checkout-taskcluster-taskgraph-v1 from /home/generic-worker/caches/Z61qSBPWQiK1zru4fUv9Zw to /home/task_djD_mCb_QnOFl_0/cache2
[taskcluster 2026-10-14T06:53:52.328Z] [mounts] Creating directory /home/task_djD_mCb_QnOFl_0
[taskcluster 2026-10-14T06:53:52.339Z] [mounts] Successfully mounted writable directory cache '/home/task_djD_mCb_QnOFl_0/cache2'
[taskcluster 2026-10-14T06:53:52.340Z] [d2g] Using cached docker image "docker.io/mozillareleases/taskgraph:run-task-v24.3.0@sha256:1efe26cb74bd09fa0f2a051b4559ab7cde4270d92f4e7c7dce7242468a21e6af"
[taskcluster 2026-10-14T06:53:52.343Z] Executing command 0: docker run -t --name taskcontainer_ZOVK5r4wS9WP6QF2petMfg --memory-swap -1 --pids-limit -1 --pull=never --log-driver=none '--add-host=localhost.localdomain:127.0.0.1' -v '/home/task_djD_mCb_QnOFl_0/cache0:/builds/worker/.cache/uv' -v '/home/task_djD_mCb_QnOFl_0/cache1:/builds/worker/.cache/pre-commit' -v /home/task_djD_mCb_QnOFl_0/cache2:/builds/worker/checkouts --network gw-task-djD_mCb_QnOF-0 '--add-host=taskcluster:172.18.0.1' --env-file 'env.list' -- 'mozillareleases/taskgraph:run-task-v24.3.0@sha256:1efe26cb74bd09fa0f2a051b4559ab7cde4270d92f4e7c7dce7242468a21e6af' run-task --src-checkout=/builds/worker/checkouts/src --task-cwd=/builds/worker/checkouts/src -- bash -c 'uv tool install pre-commit && /builds/worker/.local/bin/pre-commit run --all-files'
[setup 2026-10-14T06:53:52.574+00:00] run-task started in /
[setup 2026-10-14T06:53:52.574+00:00] Invoked by command: --src-checkout=/builds/worker/checkouts/src --task-cwd=/builds/worker/checkouts/src -- bash -c uv tool install pre-commit && /builds/worker/.local/bin/pre-commit run --all-files
[setup 2026-10-14T06:53:52.575+00:00] Python version: 3.13.5
[setup 2026-10-14T06:53:52.575+00:00] Subprocess python version: 
cpython-3.13.5-linux-x86_64-gnu    /usr/bin/python3.13
cpython-3.13.5-linux-x86_64-gnu    /usr/bin/python3 -> python3.13
[cache 2026-10-14T06:53:52.658+00:00] cache /builds/worker/.cache/uv exists; requirements: gid=1000 uid=1000 version=1
[cache 2026-10-14T06:53:52.658+00:00] cache /builds/worker/.cache/pre-commit exists; requirements: gid=1000 uid=1000 version=1
[cache 2026-10-14T06:53:52.658+00:00] cache /builds/worker/checkouts exists; requirements: gid=1000 uid=1000 version=1
[setup 2026-10-14T06:53:52.659+00:00] running as worker:worker
[vcs 2026-10-14T06:53:52.659+00:00] executing ['git', 'config', '--global', '--add', 'safe.directory', '/builds/worker/checkouts/src']
[vcs 2026-10-14T06:53:52.661+00:00] executing ['git', 'config', '--global', 'checkout.workers', '0']
[vcs 2026-10-14T06:53:52.664+00:00] executing ['git', 'remote', 'set-url', 'origin', 'https://github.com/jcristau/taskgraph']
[vcs 2026-10-14T06:53:52.666+00:00] executing ['git', 'fetch', 'origin', 'perf-generator-fork']
[vcs 2026-10-14T06:53:52.934+00:00] From https://github.com/jcristau/taskgraph
[vcs 2026-10-14T06:53:52.934+00:00]  * branch              perf-generator-fork -> FETCH_HEAD
[vcs 2026-10-14T06:53:52.935+00:00]  * [new branch]        perf-generator-fork -> origin/perf-generator-fork
[vcs 2026-10-14T06:53:52.937+00:00] executing ['git', 'checkout', '-f', '-B', 'perf-generator-fork', 'e449cfb0c642d5050b1f07876f1dc0e4e1ba1783']
[vcs 2026-10-14T06:53:52.943+00:00] Switched to a new branch 'perf-generator-fork'
[vcs 2026-10-14T06:53:52.944+00:00] cleaning git checkout...
[vcs 2026-10-14T06:53:52.944+00:00] executing ['git', 'clean', '-nxdff']
[vcs 2026-10-14T06:53:52.947+00:00] removing ['/builds/worker/checkouts/src/.ruff_cache/']
[vcs 2026-10-14T06:53:52.948+00:00] successfully cleaned git checkout!
[vcs 2026-10-14T06:53:52.949+00:00] TinderboxPrint:<a href='https://github.com/jcristau/taskgraph/commit/e449cfb0c642d5050b1f07876f1dc0e4e1ba1783' title='Built from taskgraph commit e449cfb0c642d5050b1f07876f1dc0e4e1ba1783'>e449cfb0c642d5050b1f07876f1dc0e4e1ba1783</a>
PERFHERDER_DATA: {"framework": {"name": "vcs"}, "suites": [{"extraOptions": ["projects/887720501152/machineTypes/c3d-standard-4"], "lowerIsBetter": true, "name": "pull", "shouldAlert": false, "subtests": [], "value": 0.271223783493042}, {"extraOptions": ["projects/887720501152/machineTypes/c3d-standard-4"], "lowerIsBetter": true, "name": "update", "shouldAlert": false, "subtests": [], "value": 0.006563901901245117}, {"extraOptions": ["projects/887720501152/machineTypes/c3d-standard-4"], "lowerIsBetter": true, "name": "purge", "shouldAlert": false, "subtests": [], "value": 0.0041849613189697266}, {"extraOptions": ["projects/887720501152/machineTypes/c3d-standard-4"], "lowerIsBetter": true, "name": "overall", "shouldAlert": false, "subtests": [], "value": 0.2837941646575928}, {"extraOptions": ["projects/887720501152/machineTypes/c3d-standard-4"], "lowerIsBetter": true, "name": "overall_pull", "shouldAlert": false, "subtests": [], "value": 0.2837941646575928}, {"extraOptions": ["projects/887720501152/machineTypes/c3d-standard-4"], "lowerIsBetter": true, "name": "overall_pull_fullcheckout", "shouldAlert": false, "subtests": [], "value": 0.2837941646575928}]}
[setup 2026-10-14T06:53:52.950+00:00] UV_CACHE_DIR is /builds/worker/.cache/uv
[task 2026-10-14T06:53:52.950+00:00] executing ['bash', '-c', 'uv tool install pre-commit && /builds/worker/.local/bin/pre-commit run --all-files']
[task 2026-10-14T06:53:52.963+00:00] Resolved 11 packages in 3ms
[task 2026-10-14T06:53:52.966+00:00] warning: Failed to hardlink files; falling back to full copy. This may lead to degraded performance.
[task 2026-10-14T06:53:52.966+00:00]          If the cache and target directories are on different filesystems, hardlinking may not be supported.
[task 2026-10-14T06:53:52.966+00:00]          If this is intentional, set `export UV_LINK_MODE=copy` or use `--link-mode=copy` to suppress this warning.
[task 2026-10-14T06:53:52.981+00:00] Installed 11 packages in 16ms
[task 2026-10-14T06:53:52.981+00:00]  + cfgv==3.5.0
[task 2026-10-14T06:53:52.981+00:00]  + distlib==0.4.3
[task 2026-10-14T06:53:52.981+00:00]  + filelock==4.1.1
[task 2026-10-14T06:53:52.981+00:00]  + identify==2.6.20
[task 2026-10-14T06:53:52.981+00:00]  + nodeenv==1.11.0
[task 2026-10-14T06:53:52.981+00:00]  + packaging==26.3
[task 2026-10-14T06:53:52.981+00:00]  + platformdirs==4.13.0
[task 2026-10-14T06:53:52.981+00:00]  + pre-commit==4.7.0
[task 2026-10-14T06:53:52.981+00:00]  + python-discovery==1.6.2
[task 2026-10-14T06:53:52.982+00:00]  + pyyaml==6.0.3
[task 2026-10-14T06:53:52.982+00:00]  + virtualenv==21.14.7
[task 2026-10-14T06:53:52.982+00:00] Installed 1 executable: pre-commit
[task 2026-10-14T06:53:52.983+00:00] warning: `/builds/worker/.local/bin` is not on your PATH. To use installed tools, run `export PATH="/builds/worker/.local/bin:$PATH"` or `uv tool update-shell`.
[task 2026-10-14T06:53:53.296+00:00] trim trailing whitespace.................................................Passed
[task 2026-10-14T06:53:53.358+00:00] fix end of files.........................................................Passed
[task 2026-10-14T06:53:53.481+00:00] check yaml...............................................................Passed
[task 2026-10-14T06:53:53.550+00:00] check for added large files..............................................Passed
[task 2026-10-14T06:53:53.583+00:00] ruff (legacy alias)......................................................Passed
[task 2026-10-14T06:53:53.619+00:00] ruff format..............................................................Passed
[task 2026-10-14T06:53:53.641+00:00] uv-lock..................................................................Passed
[task 2026-10-14T06:53:53.867+00:00] yamllint.................................................................Passed
[task 2026-10-14T06:53:54.123+00:00] codespell................................................................Passed
[taskcluster 2026-10-14T06:53:54.736Z]                        Exit Code: 0
[taskcluster 2026-10-14T06:53:54.736Z]                        User Time: 10.8ms
[taskcluster 2026-10-14T06:53:54.736Z]                      Kernel Time: 14.4ms
[taskcluster 2026-10-14T06:53:54.736Z]                        Wall Time: 2.393299265s
[taskcluster 2026-10-14T06:53:54.736Z]  Average Available System Memory: 14.39 GiB
[taskcluster 2026-10-14T06:53:54.736Z]       Average System Memory Used: 1.23 GiB
[taskcluster 2026-10-14T06:53:54.736Z]          Peak System Memory Used: 1.35 GiB
[taskcluster 2026-10-14T06:53:54.736Z]              Total System Memory: 15.61 GiB
[taskcluster 2026-10-14T06:53:54.736Z]                           Result: SUCCEEDED
[taskcluster 2026-10-14T06:53:54.737Z] === Task Finished ===
[taskcluster 2026-10-14T06:53:54.737Z] Task Duration: 2.394072305s
[taskcluster 2026-10-14T06:53:54.772Z] [mounts] Preserving cache: Moving "/home/task_djD_mCb_QnOFl_0/cache0" to "/home/generic-worker/caches/GhSW4QmlS8eLo9ckMSO1pQ"
[taskcluster 2026-10-14T06:53:54.772Z] [mounts] Preserving cache: Moving "/home/task_djD_mCb_QnOFl_0/cache1" to "/home/generic-worker/caches/d3lIxFxqSfmcAkumaIq3FQ"
[taskcluster 2026-10-14T06:53:54.772Z] [mounts] Preserving cache: Moving "/home/task_djD_mCb_QnOFl_0/cache2" to "/home/generic-worker/caches/Z61qSBPWQiK1zru4fUv9Zw"