Platform/Features/Incremental GC/TestPlan

Incremental Garbage Collection

Feature	Status	Release Target	Dev Lead	QA Lead	Status
Incremental GC	Landed	Firefox 15	Bill McCloskey	Ioana Budnar	In Progress

Summary

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

References

• Wiki page

Use Cases

• Use Firefox with incremental garbage collection enabled. When IGC is enabled, dynamic content on the web should have more tolerable pauses (possibly go from noticeable pauses to ones the user cannot notice).
• Disable incremental garbage collection.

Test Cases

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

Important Bugs

Full Query

ID	Summary	Priority	Status
728686	JS_NewPropertyIterator disables IGC	--	VERIFIED
728692	Javascript becomes slow after Incremental GC gets disabled	--	RESOLVED
728976	Debug-only incremental GC crash [@ js::ReentrancyGuard::ReentrancyGuard]	--	RESOLVED
729773	[IncrementalGC] "Assertion failure: IsMarkedOrAllocated(static_cast<Cell *>(thing))" with adoptNode, gczeal(4)	--	RESOLVED
730853	If incremental GC or compartment GC runs all the time, CC never runs	--	VERIFIED
734946	Disable incremental GC for Firefox 13	--	VERIFIED
735099	Re-enable incremental GC on desktop platforms	--	RESOLVED
735944	about:support says "incremental gc: 1" when javascript.options.mem.gc_incremental is disabled	--	VERIFIED
752098	Crashes on MemBench with incremental GC enabled	--	RESOLVED
759522	OOM during mochitest-other	--	RESOLVED
761739	incremental GCs are very rare	--	RESOLVED

11 Total; 0 Open (0%); 7 Resolved (63.64%); 4 Verified (36.36%);

Not Tested

• Cycle collector.

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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.