Platform/Features/Incremental GC/TestPlan

Incremental Garbage Collection

Feature	Status	Release Target	Dev Lead	QA Lead	QA Status
Incremental GC	Landed	Firefox 16	Bill McCloskey	Ioana Budnar	Signed off on Aurora

Summary

• Garbage collection time is divided into short increments. Overall, the same amount of time is spent doing garbage collection, but each individual pause is shorter.

References

• Wiki page
• Tracking bug

Use Cases

• Use Firefox with incremental garbage collection enabled:
  • Dynamic content on the web should have more tolerable pauses (possibly go from noticeable pauses to ones the user cannot notice).
  • Most GCs, if not all, should be incremental.
  • Incremental GC parameters should have acceptable values (slices with Marks <=20ms, Max Pauses <=16ms, or at least shorter than the total for Mark).
• Disable incremental garbage collection.

Test Cases

• The test cases for this feature can be viewed here.

Important Bugs

Bugzilla query error

Array ( [type] => error [message] => http-bad-status [params] => Array ( [0] => 406 [1] => Not Acceptable ) ) 1

Not Tested

• Cycle collector.

Sign off

Criteria

• All the test cases were executed.
• All the major bugs have been fixed.

Sign offs

• Firefox 13.0 Aurora - 2012-03-19
• Firefox 15.0 Aurora - 2012-06-08
  • bugs 761739, 728692, 728976, 729773, 759522 still not fixed.
• Firefox 16.0 Aurora - 2012-07-20
  • 30%-40% of the IGCs have long slices, but they all have acceptable Mark values (<20ms).
  • 10%-20% of the IGCs have Max Pause longer than the total for Mark.