testSysStat.add(-int64(p.summaryMappedReady))

	// Free the mapped space for chunks.
	for i := range p.chunks {
		if x := p.chunks[i]; x != nil {
			p.chunks[i] = nil
			// This memory comes from sysAlloc and will always be page-aligned.
			sysFree(unsafe.Pointer(x), unsafe.Sizeof(*p.chunks[0]), testSysStat)
		}
	}
}

// BaseChunkIdx is a convenient chunkIdx value which works on both