Re: [PATCH-tip v6 01/20] locking/rwsem: Prevent decrement of reader count before increment

[Waiman Long]

On 4/28/19 11:57 AM, Waiman Long wrote:
> During my rwsem testing, it was found that after a down_read(), the
> reader count may occasionally become 0 or even negative. Consequently,
> a writer may steal the lock at that time and execute with the reader
> in parallel thus breaking the mutual exclusion guarantee of the write
> lock. In other words, both readers and writer can become rwsem owners
> simultaneously.

I would like to have this particular patch merged in the next merge
window, if possible, so that I can backport it downstream.

Thanks,
Longman