The TSX Hotspots analysis type uses event-based sampling collection and is targeted for the Intel® processors supporting Intel Transactional Synchronization Extensions (Intel TSX).
This analysis type uses the the INST_RETIRED.PREC_DIST hardware event that emulates precise clockticks and helps identify performance-critical program units inside transactions.
To use the TSX Hotspots analysis type, explore:
Configuration options (knobs)
Configuration Options
To configure options for the TSX Hotspots analysis:
Click the
New Analysis toolbar button.
The Analysis Type window opens.
From the left pane, select Microarchitecture Analysis > TSX Hotspots.
The TSX Hotspots configuration pane opens on the right.
Configure the following options:
Collect stacks check box
Enable advanced collection of call stacks and thread context switches.
The default value is false.
Analyze user tasks, events, and counters check box
Analyze the tasks, events, and counters specified in your code via the ITT API. This option causes a higher overhead and increases the result size.
The default value is false.
Trace transaction cycles and instructions check box
Trace the entire application execution flow to collect reliable performance statistics inside transactions by using the Intel Processor Trace feature available for the 5th Generation Intel Core processor family. This data helps analyze instructions count and processor cycles inside transactions to compare commit and abort operations execution.
The default value is false.
Details button
Expand/collapse a section listing the default non-editable settings used for this analysis type. If you want to modify these settings for the analysis, you need to create a custom configuration by right-clicking the analysis entry in the analysis tree and selecting Copy from Current from the context menu. VTune Amplifier creates an editable copy of this analysis type configuration and locates it under the Custom Analysis branch in the analysis tree.
Click Start to launch the analysis.
Viewpoints
You can choose to view TSX Hotspots analysis results in the TSX Exploration viewpoint that includes the following windows:
Summary window displays statistics on the overall application execution.
Bottom-up window displays performance data per CPU metrics (event ratio/event count/sample count) for each program unit.
Top-down Tree window displays hotspot functions in the call tree, performance metrics for a function only (Self value) and for a function and its children together (Total value).
Event Count window displays an estimated count of PMU events selected for the analysis.
Sample Count window displays the actual number of samples collected for a processor event.
Uncore Event Count window displays a count of uncore events selected for the analysis. If there are no uncore events, the upper pane of the window is empty.
Platform window provides details on tasks specified in your code with the Task API, Ftrace*/Systrace* event tasks, OpenCL™ API tasks, and so on. If corresponding platform metrics are collected, the Platform window displays overtime data as GPU usage on a software queue, CPU time usage, OpenCL™ kernels data, and GPU performance per the Overview group of GPU hardware metrics, Memory Bandwidth, and CPU Frequency
Analyze the Precise Clockticks metric values to identify the most time-consuming program units inside transactions.