This tutorial explains how to collect and explore CPU profiles.

Note: If you are a Web Developer and want to get the latest version of Developer Tools, you should use the Google Chrome release from the Developer Channel.

Using Google Chrome, open the V8 Benchmark Suite page. Click the Start profiling button. The circle changes to red. Now return to the V8 Benchmark Suite page, and either press F5 or click the browser's Reload button to reload the page.

When the page has completed reloading, a score for the benchmark tests is shown. Return to the Developer Tools window and click the Stop profiling button. The circle changes to gray.

This Bottom Up view lists functions by impact on performance. It also enables you to examine the calling paths to those functions.

Now select the Top Down view by clicking the Bottom Up / Top Down selection button. Then click the small arrow to the left of (program) in the Function column. The Top Down view shows an overall picture of the calling structure, starting at the top of the call stack.

Note: You can click the Percentage button to view absolute times.

Select one of the functions in the Function column, then click the Focus selected function button (the Eye icon on the right).

This filters the profile to show only the selected function and its callers. Click the Reload button at the bottom-right of the window to restore the profile to its original state.

Select one of the functions in the Function column, then click the Exclude selected function button (the X icon). Depending on the function you selected, you should see something like this:

The Exclude selected function button removes the selected function from the profile and charges its callers with the excluded function's total time. Click the Reload button to restore the profile to its original state.

You can record multiple profiles. Click the Start profiling button, reload the V8 Benchmark page, then click the Stop profiling button.

The sidebar on the left lists your recorded profiles, the tree view on the right shows the information gathered for the selected profile.

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Last updated April 6, 2012.