# tt_process_count

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## Name

### Prometheus Metric Name

```
tt_process_count
```

### Metric Path (tt-telemetry)

Schema:

```
{hostname}/processes/tt_process_count
```

Example path:

```
bh-glx-c09u02/processes/tt_process_count
```

## Description

The number of distinct host processes *other than the telemetry collector itself* that currently hold an open handle to a Tenstorrent kernel-mode driver (KMD) device. It is computed by scanning each per-device directory under `/proc/driver/tenstorrent/`, reading the `pids` file in each, and counting the union of all PIDs. A process attached to more than one device is counted only once (duplicate PIDs are removed).

The collector opens the devices it monitors, so its own PID is removed from the union before counting. A value of `0` therefore means no process besides the telemetry collector is using the devices, rather than that the devices are entirely unused.

This is a host-level metric (not scoped to a tray or chip path). It is driver-independent: it reads procfs directly and does not require UMD/driver initialization, so it persists across warm resets. It is only created when device telemetry collection is enabled, and its value is refreshed on every collection cycle. If no Tenstorrent device directories are found under `/proc/driver/tenstorrent/`, a warning is logged and the value is reported as `0`.

## Values

**Type:** Unsigned Integer

**Units:** None

**Allowable values:** Non-negative integer representing the number of distinct processes, excluding the telemetry collector, holding a handle to any Tenstorrent device (for example `0` when only the collector has the devices open, or `3` when three other distinct processes hold handles).

## Related Metrics

|Metric|Description|
|---|---|
|[tt_chip_count](tt_chip_count.md)|Number of Tenstorrent chips discovered on the host via PCI device enumeration.|
|[tt_driver_initialized](tt_driver_initialized.md)|Whether the device driver is initialized. `tt_process_count` is assessed independently of driver initialization.|

## Prometheus Labels

|Label Name|Value|
|---|---|
|hostname|The host from which the metric was collected.|