# boost\_cpu

Source: [https://docs.qualcomm.com/doc/80-PK177-134/topic/qape_boost_cpu.html](https://docs.qualcomm.com/doc/80-PK177-134/topic/qape_boost_cpu.html)

Adds the virtual utilization on all available CPUs by a
    percentage specified by the input parameter. This load is used to calculate the CPU frequency,
    and a higher load result in a higher CPU frequency. The API call lasts for a duration of
    2 sec.
    This helps to provide a pulse boost (higher CPU frequency) for the application when a sudden
    increase in CPU load is expected. For example, scene changes in a CPU heavy game.

    boost_cpu()Copy to clipboard

## 
        Usage guidance

This API needs to be used when the application expects a load increase in the immediate
        future, causing the application to miss a deadline (such as a vsync). Since the API call
        lasts 2 sec, this hint needs to be called again if the application requires an
        extended boost duration. The expectation is for the underlying CPU DCVS software to latch
        onto the right load requirement immediately after the burst of load increase. Hence, this
        API is not expected to be called repeatedly, but only to prime the underlying CPU DCVS
        for the upcoming sudden burst of load to account for an increase in CPU load ahead of time.
        Negative boost can be used to reduce utilization for custom low-power use cases.

Note: This API can only be invoked 3 times in a 10 sec interval.

Note: The boost\_cpu API is intended only for OEM use. There is no third-party support.

## Parameters

| Parameters | API type | Data type | Description |
| --- | --- | --- | --- |
| boost\_val | Java | int | Boost the utilization on CPU by boost\_val%. This is the amount of<br>                CPU utilization that is boosted.<br><br><br>Valid range is -50% to 400% (a negative<br>                value reduces the task utilization). |
| boost\_val | Native | int32 | Boost the utilization on CPU by boost\_val%. This is the amount of<br>                CPU utilization that is boosted.<br><br><br>Valid range is -50% to 400% (a negative<br>                value reduces the task utilization). |
| ret\_val | Native | int8\_t& | On success this is the actual return value from the API.<br><br><br>                <br><ul class="ul"><br>                    <li class="li">0: Success</li><br><br>                    <li class="li">-1: Failed to apply boost</li><br><br>                    <li class="li">-2: Failed to establish session; check call API set_pkg name before this<br>                      API</li><br><br>                    <li class="li">-3: Failed to request boost; exceeded the allowed boost count (3) in 10<br>                      sec</li><br><br>                  </ul> |
|  |  |  |  |

## Returns

| Return | API type | Data type | Description |
| --- | --- | --- | --- |
| response | Java | int | <ul class="ul"><br>                  <li class="li">0: Success</li><br><br>                  <li class="li">-1: Failed to apply boost</li><br><br>                  <li class="li">-2: Failed to establish session; check call API set_pkg name before this<br>                    API</li><br><br>                  <li class="li">-3: Failed to request boost; exceeded the allowed boost count (3) in 10<br>                    sec</li><br><br>                </ul> |
| response | Native | qesdk\_transaction\_status | See [QESDK transaction status for Native APIs](https://docs.qualcomm.com/doc/80-PK177-134/topic/native_qesdk_class.html) for usage details. Use qesdk\_transaction\_status to confirm API call invocation. If successful, use the `ret` value for the actual API return value object. |
|  |  |  |  |

**Parent Topic:** [QAPE subsystem APIs](https://docs.qualcomm.com/doc/80-PK177-134/topic/qape_apis.html)

## Example for boost\_val

Source: [https://docs.qualcomm.com/doc/80-PK177-134/topic/qape_boost_cpu.html](https://docs.qualcomm.com/doc/80-PK177-134/topic/qape_boost_cpu.html)

Caution:

A continuous boost may result in higher power costs and may impact the
      overall battery life. It is recommended to use when a sudden increase in CPU workload is
      expected.

If calculated utilization based on actual load of the CPU is 30, depending on boost\_cpu percentage value, each CPU utilization 
        will be updated appropriately. Range for the CPU utilization is 0 – 1024 (1024 represents max utilization of prime CPU). 
        Depending on cluster of the CPU, max utilization of a CPU can be lower (for example - silver/gold cluster) than 1024. 
        Based on utilization reported by all the CPUs of a cluster, CPU Governor scales frequency of a cluster at defined intervals.

| Current Utilization (per CPU) | Boost Val | Target Utilization (per CPU) |
| --- | --- | --- |
| 30 | -50 | 15 |
| 30 | 0 | 30 |
| 30 | 50 | 45 |
| 30 | 100 | 60 |
| 30 | 150 | 75 |
| 30 | 200 | 90 |
| 30 | 250 | 105 |
| 30 | 300 | 120 |
| 30 | 350 | 135 |
| 30 | 400 | 150 |

Last Published: Nov 14, 2024

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