Viewing a False Sharing Analysis Task

Prerequisites

A false sharing analysis task has been created and the analysis is complete.

Procedure

1. In the System Profiler area on the left, click the name of the target analysis task.

   The node list is displayed.

2. Click the name of the target node to view the analysis results.
   • Click the node name. The Summary tab page is displayed by default, as shown in Figure 1. For details about the parameters, see Table 1.
     

     The Summary tab page displays the tuning suggestions and shows the records of cache line addresses in a list view. You can expand the view to show detailed cache line data.

     Figure 1 Summary
     

     Table 1 Parameters on the Summary tab page

     Parameter	Description
     Cacheline Address	Cache line address.
     Total Records	Number of false sharing accesses.
     Rate (%)	Ratio of the number of false sharing accesses to the total number of accesses.
     Offset	Offset of the accessed memory in the current cacheline address.
     PID	Process ID.
     Code Address	Address of the accessed instruction.
     Symbol	Name of the function on which false sharing occurs.
     Target File Name	Name of the target file on which false sharing occurs.
     Source: Line	Name of the source file and code line number where false sharing occurs.
     NUMA Node	NUMA node that access the memory.

     Click a function name to view the function source code and assembly code analysis details, as shown in Figure 2. For details about the parameters, see Table 2.

     

     • The Source Code area displays the number and proportion of false sharing accesses, and the corresponding high-level language file and line number.
     • In the Assembly Code and Code Flow areas, you can perform flow control analysis on assembly code. You can see the "hot" levels of the assembly code blocks from the colors of the basic blocks and relationships between them.

     • In the Assembly Code area, you can click the up and down arrows to switch the code blocks.
     • If the Graphviz component is not installed in the OS, the tool does not support the Code Flow function.
     Figure 2 Association between function source code and assembly instructions
     

     Table 2 Parameters on the function details page

     Parameter	Description
     Total Records	Number of false sharing accesses.
     File Name	Name of the file where the current function is located.
     Source Code
     Line No.	Line number of the source code.
     Source Code	Source code.
     Count (%)	Count: number of false sharing accesses corresponding to the source code. %: percentage of the number of false sharing accesses corresponding to the source code to the total number of false sharing accesses.
     Assembly Code
     Address	Assembly instruction address.
     Line No.	Line number of the source code corresponding to the assembly instruction.
     Assembly Code	Assembly instructions executed.
     Count (%)	Count: number of false sharing accesses corresponding to the assembly instruction. %: percentage of the number of false sharing accesses corresponding to the source code to the total number of false sharing accesses.

   • Click the Task Information tab to view the detailed configuration and sampling information about the task on the current node.
     

     If the task fails to be executed, the failure cause is displayed on the Task Information tab page.

     If some data fails to be collected but the overall task execution is not affected, you can view the exception message in Exception Information.

     Collection End Cause displays the reason why the data collection of the current task ends, for example, "Task collection times up" or "File size reaches the collection limit."