Re: [RFC PATCH-tip v4 07/10] locking/rwsem: Change RWSEM_WAITING_BIAS for better disambiguation

Wanpeng Li
2016-08-19T05:57:49Z

2016-08-19 5:11 GMT+08:00 Waiman Long <Waiman.Long@hpe.com>:
> When the count value is in between 0 and RWSEM_WAITING_BIAS, there
> are 2 possibilities.
> Either a writer is present and there is no waiter

count = 0xffff0001

>or there are waiters and readers. There is no easy way to

count = 0xffff000X

However, RWSEM_WAITING_BIAS is equal to 0xffff0000, so both these two
cases are beyond RWSEM_WAITING_BIAS, right?

Regards,
Wanpeng Li