The profile types are classified based on the hardware or software sampling events used to collect the profile data.
Time-Based Profile (TBP)
In this profile, the profile data is periodically collected based on the specified OS timer interval. It is used to identify the hotspots of the profiled applications.
Event-Based Profile (EBP)
In this profile, the CPU Profiler uses the PMCs to monitor the various micro-architectural events supported by the AMD x86-based processor. It helps to identify the CPU and memory related performance issues in the profiled applications. The CPU Profiler provides several predefined EBP profile configurations. To analyze an aspect of the profiled application (or system), a specific set of relevant events are grouped and monitored together. The CPU Profiler provides a list of predefined event configurations, such as Assess Performance and Investigate Branching. You can select any of these predefined configurations to profile and analyze the runtime characteristics of your application. You also can create their custom configurations of events to profile.
In this profile mode, a delay called skid occurs between the time at which the sampling interrupt occurs and the time at which the sampled instruction address is collected. This skid distributes the samples in the neighborhood near the actual instruction that triggered a sampling interrupt. This produces an inaccurate distribution of samples and events are often attributed to the wrong instructions.
Instruction-Based Sampling (IBS)
In this profile, the CPU Profiler uses the IBS HW supported by the AMD x86-based processor to observe the effect of instructions on the processor and on the memory subsystem. In IBS, HW events are linked with the instruction that caused them. Also, HW events used by the CPU Profiler to derive various metrics, such as data cache latency.
Custom Profile
This profile allows a combination of HW PMC events, OS timer, and IBS sampling events.