Fixing macOS High CPU Usage in dasd Process with Antigravity

Today, my Mac (running the latest macOS 27.0 beta 8) suddenly started lagging. Opening Activity Monitor revealed that a system process named dasd was pinning a single CPU core at 90%–120%. A quick search yielded no useful answers. Tracing it down with Google Antigravity, I uncovered a hilarious blunder: an infinite loop caused by an Apple engineer handling time zones incorrectly.

TL;DR — Run this command directly:

defaults write com.apple.appstored ArcadePayoutResetDate \
  -date "$(date -v+3d -u +"%Y-%m-%dT%H:%M:%SZ")" && \
  killall appstoreagent

Troubleshooting Process with Google Antigravity

Conclusion & Current Status (BLUF)

dasd continuously consuming 90%–99% CPU is not routine background system maintenance, but rather appstoreagent (the App Store background daemon) trapped in a hyperactive scheduling loop.

The root cause has been isolated and resolved. CPU usage for dasd dropped from 98.1% to 0.0%, and the system returned to normal without requiring a reboot.

Root Cause Analysis

Unified Logging System captures and process call traces provided clear evidence of the infinite loop:

1. Offending Task: com.apple.appstored.ArcadeResetPO (Apple Arcade payout metrics reset task).
2. Logic Flaw:
   • The actual current time was in the afternoon, but ArcadePayoutResetDate in com.apple.appstored preferences was pinned to midnight earlier that day: 2026-09-06 00:00:00 +0800 (a timestamp in the past).
   • After finishing the reset, appstoreagent failed to advance the timestamp to the next cycle (the following day). Instead, it re-registered the task using the already expired timestamp 2026-09-06 00:00:00.
   • When dasd (Duet Activity Scheduler) received the registration, it saw that the scheduled execution time was in the past, marked it as overdue, and triggered it immediately (Running immediately on submission).
   • Outcome: Over 400 dispatch and IPC events triggered per second, keeping dasd pegging a full CPU core continuously.

Unified Log Trace

appstoreagent: [ArcadePayoutReset] Payout metrics reset with current payout reset time: 2026-09-06 00:00:00+0800
appstoreagent: [ArcadePayoutReset] Reset with reason: Rescheduling
appstoreagent: [ArcadePayoutReset] Using new date: 2026-09-06 00:00:00+0800 with reason: Rescheduling
appstoreagent: [ArcadePayoutReset] Activity not scheduled; submitting request
dasd:          SUBMITTING: 501:com.apple.appstored.ArcadeResetPO
dasd:          Running immediately on submission
dasd:          REQUESTING START: 501:com.apple.appstored.ArcadeResetPO

Mitigation & Verification

The loop was broken by manually pushing the scheduled date forward in user defaults and gracefully restarting appstoreagent:

1. Command Executed: defaults write com.apple.appstored ArcadePayoutResetDate -date "2026-09-06T16:00:00Z" && killall appstoreagent
2. Verification Results:
   • Monitored via top / ps: dasd (PID 404) CPU usage instantly fell to 0.0%.
   • After restarting, appstoreagent suspended normally and stopped flooding the system log at 400+ entries/sec.

After working through the trace with Google Antigravity, CPU usage is back to normal.