Bug 292695 – Allocate compactible and non-compactible types out of entirely different heaps

• Status: RESOLVED
• Resolution: FIXED
• Component: bmalloc

[David Degazio]

Previously we introduced a notion of compact allocated types/modes at the bmalloc and libpas levels, where we distinguish between allocations that we want to compress pointers to v.s. allocations we don't. Currently, we allow some ambiguity, where most of these allocations are "maybe compact", i.e. allocated out of a space that is not tacitly compactible. But to move towards being able to compress pointers across the board, we want to introduce some capability of allocating compactible allocations out of specific heaps. To start, we'll lay the groundwork for allocating all existing compact allocations (whether through TZone heaps or allocated generally from the intrinsic bmalloc heap) from wholly distinct pas heaps from non-compact allocations. This essentially means we will no longer do "maybe compact" allocations on trunk, and lay a foundation for us to be able to do more sophisticated per-heap compact pointers in the future.

[Radar WebKit Bug Importer]

<rdar://problem/150893097>

[David Degazio]

Pull request: https://github.com/WebKit/WebKit/pull/45449

[EWS]

Committed 295119@main (bf96ec01cb51): <https://commits.webkit.org/295119@main>

Reviewed commits have been landed. Closing PR #45449 and removing active labels.