{"version":"2.1.296","anchor":"hooks-worker-thread-cpu-sampling-on-linux","canonical_anchor":"hooks-worker-thread-cpu-sampling-on-linux","heading":"Claude Code now measures the hooks worker's CPU use on Linux and WSL","tier":"internal","area":"Hooks","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.296\/e\/hooks-worker-thread-cpu-sampling-on-linux","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.296","markdown":"### Claude Code now measures the hooks worker's CPU use on Linux and WSL\n\nOn Linux and WSL, Claude Code names the thread that runs hooks and reads its CPU time and sleep state from the system\n\n**What**\n\nHooks are your own commands that Claude Code runs at set moments. Claude Code runs them on a worker, a separate thread working alongside the main program. On Linux and WSL (Windows Subsystem for Linux), that worker is now given a name, and Claude Code reads the system's per-thread files under `\/proc\/self\/task` to measure how much CPU time the worker has used and whether it is asleep.\n\n**Why**\n\nThis gives Claude Code a way to diagnose a hooks worker that has stalled.\n\n- Area: Hooks\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: no"}