## AIVA PRD: Enhanced Frequency Scaling Hysteresis

This PRD focuses on implementing hysteresis for frequency scaling *down*, complementing the previously implemented hysteresis for scaling up. This will prevent rapid oscillation between frequency levels due to minor fluctuations in CPU load.

### GPM-048: Implement Basic Hysteresis for Frequency Scaling Down
**Goal:** Implement hysteresis to the CPU frequency scaling logic when scaling *down* the frequency. This will require a smaller threshold to trigger a decrease compared to the threshold that would trigger an increase.
**Acceptance Criteria:**
- When CPU load drops below the "downscale threshold," the frequency remains at its current level.
- The frequency only decreases when the CPU load remains below the "downscale threshold" for a specified period (e.g., 5 seconds).
- The "downscale threshold" is lower than the "upscale threshold" defined in GPM-047.
**Files:** `aiva/frequency_scaling.py`
**Spawns:** Implement configurable hysteresis parameters.

### GPM-049: Introduce Configuration Parameters for Hysteresis Thresholds
**Goal:** Make the "upscale threshold" and "downscale threshold" configurable via a configuration file or command-line arguments.
**Acceptance Criteria:**
- The "upscale threshold" and "downscale threshold" can be set through a configuration file.
- The system defaults to reasonable values for these thresholds if they are not specified in the configuration file.
- Changes to the configuration file are reflected in the frequency scaling behavior without requiring a system reboot (if possible, or a graceful restart).
**Files:** `aiva/config.py`, `aiva/frequency_scaling.py`, `config/aiva.conf` (example)
**Spawns:** Implement configurable hysteresis duration.

### GPM-050: Introduce Configuration Parameter for Hysteresis Duration
**Goal:** Make the duration that the CPU load must remain below the downscale threshold (before scaling down) configurable.
**Acceptance Criteria:**
- The hysteresis duration can be configured via a configuration file or command-line arguments.
- The system defaults to a reasonable duration (e.g., 5 seconds) if not specified.
**Files:** `aiva/config.py`, `aiva/frequency_scaling.py`, `config/aiva.conf` (example)
**Spawns:** Implement adaptive hysteresis duration based on workload characteristics.

### GPM-051: Implement Logging for Frequency Scaling Decisions
**Goal:** Add logging to track when frequency scaling decisions are made, including the CPU load, current frequency, thresholds, and duration.
**Acceptance Criteria:**
- Log messages are generated when the frequency is scaled up or down.
- Log messages include the CPU load at the time of the decision.
- Log messages include the current frequency before and after the scaling.
- Log messages include the applicable thresholds and duration used for the decision.
- Logging level is configurable.
**Files:** `aiva/frequency_scaling.py`, `aiva/logging_config.py`
**Spawns:** Analyze log data to optimize hysteresis parameters.

### GPM-052: Create Unit Tests for Frequency Scaling with Hysteresis
**Goal:** Create unit tests to verify the correct behavior of the frequency scaling logic with hysteresis.
**Acceptance Criteria:**
- Unit tests cover cases where the CPU load fluctuates around the thresholds.
- Unit tests verify that the frequency does not change immediately when the load crosses a threshold.
- Unit tests verify that the frequency scales up or down correctly after the hysteresis duration has elapsed.
- Unit tests cover different threshold and duration values.
**Files:** `tests/test_frequency_scaling.py`
**Spawns:** Implement integration tests for frequency scaling with other AIVA components.

### GPM-053: Document Frequency Scaling Hysteresis Implementation
**Goal:** Document the implementation of frequency scaling hysteresis, including the configuration parameters and their effects.
**Acceptance Criteria:**
- Documentation explains the purpose of hysteresis in frequency scaling.
- Documentation describes the "upscale threshold," "downscale threshold," and "hysteresis duration" parameters.
- Documentation provides examples of how to configure these parameters.
- Documentation includes information on how to interpret the frequency scaling logs.
**Files:** `docs/frequency_scaling.md`
**Spawns:** Create a user guide section on advanced frequency scaling configuration.
