2.7. Give every memory number a precise meaning🔗

The metadata schema can carry allocated bytes, live bytes, peak bytes, and a net change, but the core profiler does not manufacture those values. An allocator adapter must define which allocator was observed, when it was sampled, and what each unit means.

Two snapshots can answer a narrow question:

net change = live bytes after - live bytes before

They cannot recover every allocation or the true peak if memory was allocated and freed between the snapshots. A peak requires either a counter maintained by the allocator or an allocation event stream. Process peak RSS is different again: it is a process-wide high-water mark, not live tensor memory and not attribution to one span.

Record only the memory fields the adapter can justify. A missing field means “not measured.” It should never be displayed or compared as zero.