support for multi-range discard requests V2
From: Christoph Hellwig <hch@lst.de>
Date: 2017-02-08 13:13:39
Also in:
linux-nvme
Hi all,
this series adds support for merging discontiguous discard bios into a
single request if the driver supports it. This reduces the number of
discards sent to the device by about a factor of 5-6 for typical
workloads on NVMe, and for slower devices that use I/O scheduling
the number will probably be even bigger but I've not implemented
that support yet.
Changes since V1:
- hardcoded max ranges for NVMe to 255
- minor cleanups