Windows Desktop 26.707: sustained Electron main-process CPU/memory loop persists without Git

What happened?

Codex Desktop for Windows is unusably laggy on Microsoft Store package OpenAI.Codex 26.707.3748.0.

A multi-pass local diagnostic run found a sustained Electron/Chromium main-process background loop while the app is idle:

• approximately 86–113% of one logical CPU core
• private memory repeatedly cycling between roughly 0.3 and 2.4 GB
• approximately 120,000–140,000 page faults/sec
• approximately 500 MB/sec of logical read I/O
• ETW measured only 151,552 bytes of physical reads over 32.45 seconds, so this is logical/cached/native churn rather than a storage bottleneck
• a scheduler trace independently measured 95.6% of one logical core
• the available sampled main-thread CPU was concentrated in a narrow chrome.dll RVA range; packaged symbols were unavailable

The GPU and renderer helper processes remained comparatively cold.

Background work observed

Procmon showed repeated Git snapshot commands:

• git config --null --get core.fsmonitor
• git status --renames --porcelain=v1 -z --untracked-files=no
• git add -u
• git ls-files --others --exclude-standard -z
• git read-tree
• git add --pathspec-from-file=- --pathspec-file-nul
• git write-tree

It also showed repeated bundled-marketplace staging/reconciliation. These amplify the problem, but they do not appear to be the primary trigger.

Controlled tests

The main-process storm remained after each reversible control:

• fresh logs database
• empty session/history profile
• 15 configured plugins disabled and memories off
• workspace with no .git directory
• temporary initial Git commit
• completely clean committed repository
• app window minimized

Representative CPU averages (% of one logical core):

| Control | CPU avg | P95 | Logical reads |
|---|---:|---:|---:|
| Initial idle | 86.32% | 118.52% | 532.7 MB/s |
| Empty history | 91.92% | 116.96% | 542.6 MB/s |
| Configured plugins disabled | 97.94% | 126.68% | 505.1 MB/s |
| No Git repository | 112.67% | 165.69% | 565.4 MB/s |
| Clean committed repository | 89.01% | 115.67% | 520.1 MB/s |

The minimized-window control still used 116.1% of one core and accumulated 7.84 GB of logical reads in 15 seconds.

Environment

• Windows 11 x64
• 32 GB RAM
• 12 logical CPUs
• ample free NVMe space
• Microsoft Store Codex package 26.707.3748.0
• app package status reports OK
• Store update completed before final testing

Expected behavior

The desktop main process should become mostly idle when no task is active and should not continuously churn CPU, private memory, process metrics, Git snapshots, or logical reads.

Related reports

This appears related to #22085, #20933, #17229, #15620, and #22912. #22085 is closed as completed, but the problem still reproduces in 26.707.3748.0 and persists after removing Git from the workspace.

Additional evidence

A sanitized private support bundle is available containing derived telemetry summaries and restoration results. Raw Procmon/ETL traces, databases, sessions, config, authentication data, usernames, and local paths are intentionally not attached publicly.