781849 - Split out analysis data that lives across collections from analysis-temporary in about:memory

Status: RESOLVED DUPLICATE of bug 789398

(Core :: JavaScript Engine, defect)

Description

[Andrew McCreight [:mccr8]]

See https://bugzilla.mozilla.org/show_bug.cgi?id=781767#c4

(In reply to Brian Hackett (:bhackett) from comment #4)
> A separate thing is that even when a GC clears analysis-temporary data,
> usage will not go to zero; the bucket describes an allocator that is cleared
> on each GC but is then immediately refilled with certain data that has to
> live across collections.  Bug 778724 also improves this, by splitting the
> allocator in two, and memory reporting could be improved as a followup to
> distinguish the two allocators (the current patch gloms them together).

Comment 1

[Nicholas Nethercote [inactive]]

In bug 775382 I saw the analysis-temporary numbers go negative, which indicates that it's possible for something to go wrong within the size computation.  In general, straight measurements of allocated memory (e.g. with malloc_usable_size) are preferable to computed sizes, because computed sizes are error-prone.  (https://wiki.mozilla.org/Memory_Reporting#Two_Ways_to_Measure has more details.)  So if the subtractions can be removed as part of this change, that would be great.

Comment 2

[Andrew McCreight [:mccr8]]

Nick, is this a dupe of bug 789398?

Comment 3

[Nicholas Nethercote [inactive]]

Yes!  Thanks.