Problem with performance tab readings in task manager

If you are seeing the total CPU graph flatline into a horizontal line while individual logical processors continue moving, this is caused by a confirmed off-by-one bug in TaskManagerDataLayer.dll.

What is happening

1. Task Manager queries process information via NtQuerySystemInformation. If process creation occurs during the query, the buffer overflows (STATUS_INFO_LENGTH_MISMATCH), triggering a retry loop (up to 3 times).
2. Due to an off-by-one in the retry counter check in ProcessDataGenerator::QueryProcessInformation (RVA 0x46158), exhausting all 3 retries is mistakenly treated as success (S_OK), publishing a truncated buffer.
3. The truncated buffer ends with a zeroed ghost record {PID 0, CreateTime 0}.
4. Downstream BaseAggregationManager indexes processes by PID only and already holds the real System Idle Process {PID 0, CreateTime != 0}. The CreateTime mismatch triggers invariant error 0x8007139F (ERROR_INVALID_STATE).
5. This uncaught exception permanently terminates the background async update loop (Core::DoAsyncWork). The total CPU graph keeps redrawing the last cached reading (the flat line).

Workaround & Status

Restarting Task Manager resets the data layer until the next burst of process creations triggers the condition again. Only Microsoft can fix the underlying retry boundary check.

• Upvote the official report in Feedback Hub: https://aka.ms/AA13rk15
• Full technical writeup & reproducible probe: https://github.com/lurunzi/taskmgr-flatline-watch

Hi Ryu,

I understand your concern. Based on your description, if the CPU graph in Task Manager > Performance starts updating a little later than the Memory, Disk, or GPU graphs but then loads and works normally, this is generally considered normal behavior and does not usually indicate a problem with your CPU or system performance.

To better understand whether this is expected or a specific issue on your system, could you let me know:

• Are you using Windows 10 or Windows 11?
• Approximately how long does the CPU graph take to appear?
• Does the graph eventually load and update normally, or does it remain blank/frozen?

In the meantime, please try the following:

1. Open Resource Monitor by pressing Windows + R, typing resmon, and pressing Enter.
2. Verify whether CPU activity appears normally there.
3. Open Task Manager multiple times and observe whether the delay is only brief.
4. If the CPU graph eventually loads and updates correctly while the system performs normally, the behavior is likely cosmetic rather than a performance issue.

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