Re: [PATCH v3 0/2] Prevent non-NCQ command starvation

[Niklas Cassel <cassel@kernel.org>]

On Sat, Dec 20, 2025 at 09:21:38AM +0900, Damien Le Moal wrote:
> This small patch series addresses potential command starvation issues
> with non-NCQ passthrough commands issued to a device accessed through

Here and everywhere else:
s/non-NCQ passthrough commands/non-NCQ commands/

The problem is really not related to passthrough commands,
but rather the mix between NCQ and non-NCQ commands.

E.g. you can perform a ioctl with the REQ_OP_DISCARD command,
for most ATA devices this is a SCSI WRITE SAME 16 CMD, which gets
translated to either a NCQ or non-NCQ command depending on if the
device supports NCQ encapsulated Data Set Management (DSM) commands,
and specifically if the device has the QUEUED DATA SET MANAGEMENT
SUPPORTS TRIM bit set or not, which is not a given.

TL;DR: the starvation problem is not directly tied to non-NCQ
passthrough commands, but any command, even commands that goes via
the block layer, that happens to be translated to a non-NCQ command.


Kind regards,
Niklas