Intel® VTune™ Amplifier XE and Intel® VTune™ Amplifier for Systems Help
Similar to the Top-down window, available in GUI, the Top-down represents call sequences (stacks) detected during collection phase starting from the application root. Use the top-down report to explore the call sequence flow of the application and analyze the time spent in each program unit and on its callees.
Intel® VTune™ Amplifier collects information about program unit callees only during User-Mode Sampling and Tracing Collection or Hardware Event-based Sampling Collection with Stacks with stack collection enabled.
Example 1: Basic Hotspots Top-down Report
This example displays the report for the specified Basic Hotspots analysis result with functions stacks limited to 5 elements.
$ amplxe-cl -report top-down -r r001hs -limit 5
Function Stack CPU Time:Total CPU Time:Effective Time:Total CPU Time:Spin Time:Total CPU Time:Overhead Time:Total
---------------------- -------------- ----------------------------- ------------------------ ----------------------------
Total 100.000% 100.000% 100.000% 100.000%
func@0x6b2daccf 99.853% 99.835% 100.000% 100.000%
func@0x6b2dacf0 99.853% 99.835% 100.000% 100.000%
BaseThreadInitThunk 99.853% 99.835% 100.000% 100.000%
thread_video 95.614% 97.876% 78.195% 0.0%Example 2: Advanced Hotspots Report with Enabled Call Stack Collection
This command runs the Advanced Hotspots analysis with enabled call stack collection.
$ amplxe-cl -collect advanced-hotspots -knob enable-stack-collection=true -- home/tachyon
The following command generates the top-down report for the previously collected result and shows the result for columns with the time:total strings in the title.
$ amplxe-cl -report top-down -r r001ah -column=time:total
Function Stack CPU Time: CPU Time: CPU Time: Context Switch Time: Context Switch Time: Context Switch Time:
Total Effective Time:Total Spin Time:Total Total Wait Time:Total Inactive Time:Total
---------------------- --------- -------------------- --------------- -------------------- -------------------- --------------------
Total 100.000% 100.000% 100.000% 100.000% 100.000% 100.000%
func@0x6b2daccf 97.595% 97.704% 89.202% 65.777% 90.121% 62.893%
func@0x6b2dacf0 97.595% 97.704% 89.202% 65.777% 90.121% 62.893%
BaseThreadInitThunk 97.595% 97.704% 89.202% 65.777% 90.121% 62.893%
threadstartex 67.091% 67.855% 8.335% 29.825% 9.027% 32.289%
...Example 3: Advanced Hotspots Report with Disabled Stack Collection
This command runs the Advanced Hotspots analysis with disabled call stack collection.
$ amplxe-cl -collect advanced-hotspots -knob enable-stack-collection=false -- home/tachyon
This command generates the top-down report for the previously collected result, and shows the result for columns with the time:total string in the title. The report does not include information about program unit callees, as it was not collected during the analysis.
$ amplxe-cl -report top-down -r r001ah -column=time:total
Function Stack CPU Time:Total CPU Time:Effective Time:Total CPU Time:Spin Time:Total
---------------------- -------------- ----------------------------- ------------------------
Total 100.000% 100.000% 100.000%
grid_intersect 50.172% 50.213% 0.0%
sphere_intersect 31.740% 31.766% 0.0%
grid_bounds_intersect 3.766% 3.769% 0.0%
pos2grid 0.778% 0.778% 0.0%
...