User interface

In the Metrics view, the horizontal axis is wall clock time. By default three metric graphs are shown.

Metrics view

The top graph is the Main thread activity chart, which uses the same colors and scales as the per-line sparkline graphs described in Source code (MAP). Linaro recommends that you read that section to help understand the Main thread activity chart.

For CUDA programs profiled with CUDA kernel analysis mode enabled, a Warp stall reasons graph also displays. This shows the warp stalls for all CUDA kernels detected in the program, using the same colors and scales as the GPU kernel graphs described in CUDA Kernel analysis. Linaro recommends that you read that section to help understand the Warp stall reasons graph.

All of the other metric graphs show how single numerical measurements vary across processes and time. Two frequently used graphs are CPU floating-point and Memory usage. However, there are many other metric graphs available, and they can all be read in the same way. Each vertical slice of a graph shows the distribution of values across processes for that moment in time. The minimum and maximum are clear, and shading is used to display the mean and standard deviation of the distribution.

A thin line means all processes had very similar values. A large shaded region means there is significant imbalance between the processes. Extra details about each moment in time appear below the metric graphs as you move the mouse over them.

The Metrics view is at the top of the user interface because it ties all the other views together. Move your mouse across one of the graphs, and a black vertical line appears on every other graph in Linaro MAP, showing what was happening at that moment in time.

You can also click and drag to select a region of time within it. All the other views and graphs now redraw themselves to show just what happened during the selected period of time, ignoring everything else. This is a useful way to isolate interesting parts of the execution of your program. To reselect the entire time range double-click or click the Select All Button select_all_icon.

The value displayed under the metric graph label is the Selection Mean. This value represents the mean value of the metric across the selected time range in the Metrics view. As the region of time selected changes, this value should represent the mean for selection, not the entire graph. Observe the different Selection Mean values in the first image and when a region of time is selected in the second image.

In this figure, a short region of time has been selected around an interesting sawtooth pattern in time in MPI_Barrier because PE 1 is causing delays.

MAP with a region of time selected

The first block accepts data in PE order, and is severely delayed. The second block is more flexible, accepting data from any PE, so that PE 1 can compute in parallel. The Source code viewer shows how compute and communication are serialized in the first block, but overlap in the second.

Changing Metrics

There are many more metrics other than those displayed by default. To change the visible metrics:

  • Click Metrics on the main menu

  • Or, right-click on the metric graphs

  • Or, click the Change Metrics button change_metrics_icon in the Metrics view

to choose one of the available presets or any combination of the metrics beneath them. For more information on available metrics, see Metrics.

The display order of metrics can be changed by left clicking the handle at the left-most point on each metric graph (to the left of the metrics label). This can be dragged to a new position in the metrics graph.

Adding more metrics to the Metrics View may result in a scroll bar appearing for navigating to these additional metrics.

You can return to the default set of metrics at any time by choosing the Preset: Default option.

Metrics Height

The height of each metric graph can be modified by selecting the Change Metrics Height icon metric_height_icon in the Metrics view. When this height is altered, it will persist in the user’s local settings between sessions. See Configuration files for more information about changing these settings.

[map metric graphs]
graph height = 50
metrics table autoresize cap = 425

These settings can also be reset by selecting Window and Default Layout in the menu options.