// Number of roots of various root types. Set by gcMarkRootPrepare.
	//
	// nStackRoots == len(stackRoots), but we have nStackRoots for
	// consistency.
	nDataRoots, nBSSRoots, nSpanRoots, nStackRoots int

	// Base indexes of each root type. Set by gcMarkRootPrepare.
	baseData, baseBSS, baseSpans, baseStacks, baseEnd uint32

	// stackRoots is a snapshot of all of the Gs that existed

	// the concurrent phase will be caught by the write barrier.
	work.stackRoots = allGsSnapshot()
	work.nStackRoots = len(work.stackRoots)

	work.markrootNext = 0
	work.markrootJobs = uint32(fixedRootCount + work.nDataRoots + work.nBSSRoots + work.nSpanRoots + work.nStackRoots)

	// Calculate base indexes of each root type
	work.baseData = uint32(fixedRootCount)