Suitability Report, Site Details, Site Row

If you choose a Target System of CPU, to view detailed characteristics of the selected site and its tasks and locks, click the Site Details tab.

The Selected Site row shows the overall statistics for the Selected Site. Below the Selected Site row, view the Tasks and Locks executed in this Site, including the Number of Instances and Total Serial Time for the entire site and each task and lock within the site.

You can reduce Site overhead by combining multiple site execution into a single site execution, for example putting a site outside a loop instead of inside a loop (moving a loop surrounding a site to be inside of the site). Under Runtime Modeling, you can view the predicted site overhead values and other predicted overhead or lock contention values (see below).

For Each Site, Decide Whether to Modify or Keep Annotations

Use the Suitability Report window to view the predicted parallel performance of each parallel site and its impact on the Maximum Program Gain for All Sites. For example, if a site either has a Site Gain of less than 1.0 or does not contribute to Maximum Program Gain for All Sites, modify or remove its annotations. In contrast, any site that contributes to Maximum Program Gain for All Sites should be kept. For most sites, carefully examine the annotations, overhead assumptions, and related code.

In the upper-right part of the Suitability Report pane, if multiple parallel sites were detected during target execution, select a different Site row to display its details.

Implementing Modeling Assumptions Later When Adding Parallel Code

In the lower-right part of the Suitability Report under Runtime Modeling, changing a checkmark does not resolve an issue - it configures the modeling of your proposed parallel program execution. To implement the modeled improvements indicated by the check boxes, use specific parallel framework constructs in the Add Parallel Framework step of the workflow and consider tuning your parallel code.

For more complete information about compiler optimizations, see our Optimization Notice.