On 2021/10/27 11:38, Jens Axboe wrote:

On 10/26/21 8:22 PM, Damien Le Moal wrote:

quoted

From: Damien Le Moal <redacted>

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.

I've applied 1/9 for now, as that clearly belongs in the block tree.
Might be the cleanest if SCSI does a post tree that depends on
for-5.16/block. Or I can apply it all as they are reviewed. Let me
know.

Patch 4 & 5 are doc updates and I think they belong to the block tree too.

Patch 3 applies cleanly to libata for-5.16 branch as is, so you can take it, or
I can take it in libata tree too, whichever works for me.

As for patch 2, it applies cleanly to 5.16/scsi-queue so I guess you can take it
too, but I will defer this decision to Martin.


-- 
Damien Le Moal
Western Digital Research