Re: [PATCH RFC -next] sbitmap: fix possible io hung due to lost wakeups

[Keith Busch]

On Fri, Jun 17, 2022 at 10:11:25PM +0800, Yu Kuai wrote:
> 
> What's worse, io hung is possible in theory because wakeups might be
> missed. For example, 2 * wake_batch tags are put, while only wake_batch
> threads are worken:

Not just in theory, io hanging sounds like the problem reported here:

  https://bugzilla.kernel.org/show_bug.cgi?id=215679

I only knew that it had nothing to do with the nvme driver, though, but they
closed the bug after it stopped happening with different hardware.