systemstack(func() {
		i := gp.m.locksHeldLen
		if i >= len(gp.m.locksHeld) {
			throw("too many locks held concurrently for rank checking")
		}
		gp.m.locksHeld[i].rank = rank
		gp.m.locksHeld[i].lockAddr = uintptr(unsafe.Pointer(l))
		gp.m.locksHeldLen++

		// i is the index of the lock being acquired
		if i > 0 {
			checkRanks(gp, gp.m.locksHeld[i-1].rank, rank)
		}
		lock2(l)
	})
}

	pcvalueCache pcvalueCache

	dlogPerM

	mOS

	chacha8   chacha8rand.State
	cheaprand uint64

	// Up to 10 locks held by this m, maintained by the lock ranking code.
	locksHeldLen int
	locksHeld    [10]heldLockInfo
}

type p struct {
	id          int32
	status      uint32 // one of pidle/prunning/...
	link        puintptr
	schedtick   uint32     // incremented on every scheduler call