racereleasemergeg(newg, unsafe.Pointer(&labelSync))
		}
	}
	releasem(mp)

	return newg
}

// saveAncestors copies previous ancestors of the given caller g and
// includes info for the current caller into a new set of tracebacks for
// a g being created.
func saveAncestors(callergp *g) *[]ancestorInfo {
	// Copy all prior info, except for the root goroutine (goid 0).