Re: [PATCH v7 21/23] block: Avoid that flushing triggers a lockdep complaint

[Peter Zijlstra]

On Fri, Feb 15, 2019 at 10:26:59AM +0800, Ming Lei wrote:
> There might be lots of blk_flush_queue instance which is allocated
> for each hctx, then lots of class key slot may be wasted.

What is 'lots' ? for someone who doesn't really know all that much about
the block layer.