The GC allocation path breaks if COLLECT_ON_EVERY_ALLOCATION is set. This occurs for two reasons: 1) To collect we need JSGlobalData to be initialized, but to be initialized, JSGlobalData must perform allocations. 2) Even if this is side-stepped, the Heap::allocate() handles allocation slow cases by calling itself recursively, which always results in another forced collection if COLLECT_ON_EVERY_ALLOCATION is set. But allocating after a collection requires the slow path to be taken. Hence, COLLECT_ON_EVERY_ALLOCATION causes every allocation to recurse ad infinitum, invoking a full heap GC every time.
Created attachment 100568 [details] the patch
Attachment 100568 [details] did not pass style-queue: Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/JavaScriptCore/ChangeLog', u'Source..." exit_code: 1 Source/JavaScriptCore/heap/Heap.h:139: The parameter name "sizeClass" adds no information, so it should be removed. [readability/parameter_name] [5] Total errors found: 1 in 4 files If any of these errors are false positives, please file a bug against check-webkit-style.
Created attachment 100571 [details] the patch (fix style)
Comment on attachment 100571 [details] the patch (fix style) Clearing flags on attachment: 100571 Committed r90865: <http://trac.webkit.org/changeset/90865>
All reviewed patches have been landed. Closing bug.