// time so we can track it for the GC CPU limiter.
		//
		// Limiter event tracking might be disabled if we end up here
		// while on a mark worker.
		start := nanotime()
		track := pp.limiterEvent.start(limiterEventScavengeAssist, start)

		// Scavenge, but back out if the limiter turns on.
		released := h.pages.scavenge(bytesToScavenge, func() bool {