I am learning block layer. I found a patch in this link.
https://patchwork.kernel.org/project...ei@redhat.com/
He mentioned in it that "the default nr_requests for scheduler is too big for small queuedepth devices, and latency is increased much."
I don't understand why a too larger nr_requests can let to bad effect.
If there are few requests, wouldn't it quickly exhaust the tags and cause IO blocking?
