Suggestion Tool

How does the suggestion tool work?

Higher scores indicate more serious performance issues.

Scores are weighted by invocation count (so a non-inlined hot method called 50K times will have a higher score than one called 20K times).

Currently branch prediction failures are weight as 50% as important as hot method inline failures:

From org.adoptopenjdk.jitwatch.suggestion.AttributeSuggestionWalker:

scoreMap.put(REASON_HOT_METHOD_TOO_BIG, 1.0);
scoreMap.put(REASON_UNCERTAIN_BRANCH, 0.5);

Issues with less than 1000 invocations are not reported.