In version 5.1 of AMDuProf, a new feature has been added to provide users with information regarding the overhead associated with data collection and processing during profiling.
This feature is intended to help users understand the impact of profiling on their system and make informed decisions regarding the selection of profiling configurations.
Supported and Unsupported Profiling Types
| Profiling Type | Overhead Feature Support |
|---|---|
| OS Runtime Tracing | Not supported |
| CPU Tracing | Not supported |
| GPU Tracing | Not supported |
| OpenMP Tracing | Not supported |
| MPI Tracing | Not supported |
| GPU Profiling | Not supported |
| Live Power Profile | Not supported |
| Profiling Type | Overhead Feature Support |
|---|---|
| Hotspots | Supported |
| Threading Analysis | Supported |
| Overview | Supported |
| Investigate CPI | Supported |
| Assess Performance (Extended) | Supported |
| Investigate Instruction Access | Supported |
| Investigate Branching | Supported |
| Investigate Data Access | Supported |
| Cache Analysis | Not supported |
| Instruction Based Sampling | Not supported |
| Assess Performance | Supported |
| Time Based Sampling | Supported |
For unsupported configurations, a message stating no overhead data available for the selected configuration is displayed.
- High Overhead
- Fair Overhead
- Low Overhead
- Collection Overhead: Refers to the time required to collect data during profiling. This time is influenced by the profiling configuration and system conditions.
- Processing Overhead: Refers to the time spent processing the collected data. This is impacted by various factors, including the presence of throttling events, sampling intervals, and sampling frequencies.
- Predefined Configurations: In predefined configurations, certain events such as overview and threading have a high overhead in both data collection and processing.
- Throttling Events: If there are one or more throttling events present in either predefined or custom configurations, the processing overhead will be high, and the collection overhead will be Fair.
- Sampling Intervals and Frequencies:
- Threshold for Sampling Intervals/Frequencies: A threshold exists for sampling intervals and frequencies.
- Higher Sampling Interval/Lower Sampling Frequency: Increases collection and processing overhead.
- Lower Sampling Interval/Higher Sampling Frequency: Decreases collection and processing overhead.
This balance affects the efficiency of data collection and processing.
In addition to overhead information, you get an estimate of the profiling time based on the configuration and overhead type.
You can evaluate the overhead suggestion and decide whether to proceed with the current configuration or modify it for optimal performance. This guidance helps balance the desired profiling data and the overhead it may incur on the system.
For configurations not supported by the overhead feature, a message stating that no overhead data available for the selected configuration will be displayed.