519902 - Allocating Array from the own GC free lists

Status: RESOLVED INVALID

(Core :: JavaScript Engine, enhancement)

Description

[Igor Bukanov]

+++ This bug was initially created as a clone of Bug #517199 +++

Benchmarks from the bug 517199 indicates that for the object finalizer the check if the object is native has visible cost. A separated free list for array can address it since the array is the single non-native object. This should not have performance impact on js_NewObjectWithTheGivenProto since that function is already carries out the native/non-native check when initializing object's map. The check can be replaced with a check for the Array class which would allow to call js_NewGCArray there.

The thing to watch here would be potentially greater heap fragmentation and degraded performance due to more misses in TLB cache when a script accesses a lot of tightly allocated objects and arrays. Currently these would come most likely from one single CPU page, but with an extra list separated pages will be used.

Comment 1

[André Bargull [:anba]]

Old bug, no longer valid.