On 9/8/21 8:35 PM, Damien Le Moal wrote:

Single LUN multi-actuator hard-disks are cappable to seek and execute
multiple commands in parallel. This capability is exposed to the host
using the Concurrent Positioning Ranges VPD page (SCSI) and Log (ATA).
Each positioning range describes the contiguous set of LBAs that an
actuator serves.

This series adds support to the scsi disk driver to retreive this
information and advertize it to user space through sysfs. libata is
also modified to handle ATA drives.

The first patch adds the block layer plumbing to expose concurrent
sector ranges of the device through sysfs as a sub-directory of the
device sysfs queue directory. Patch 2 and 3 add support to sd and
libata. Finally patch 4 documents the sysfs queue attributed changes.
Patch 5 fixes a typo in the document file (strictly speaking, not
related to this series).

This series does not attempt in any way to optimize accesses to
multi-actuator devices (e.g. block IO schedulers or filesystems). This
initial support only exposes the independent access ranges information
to user space through sysfs.

Let's get this queued up for 5.16. I forgot what we agreed upon, can go
either block or SCSI. We likely have a bunch more block changes this
round than usual, and hence a higher risk of conflict, so from that
perspective alone I think the block layer would be easier.

In any case, Damien, it needs a respin as it doesn't apply against
my for-5.16/block at this point.

-- 
Jens Axboe