On 2024/10/31 22:12, Niklas Cassel wrote:
On Thu, Sep 19, 2024 at 04:14:15PM +0200, Damien Le Moal wrote:
On 2024/09/19 14:26, Yu Kuai wrote:
Does libata return a specific value in this case? If so, maybe we can
stop other hctx untill this IO is handled.
For now, I think libata should use single hctx, it just doesn't support
multiple hctx yet.
libata does not care/know about hctx. It only issues commands to ATA devices,
which always are single queue. And pure SATA adapters like AHCI are always
single queue.
The issue at hand can happen only for libsas based SAS HBAs that have multiple
command submission queues (with a shared tag set). Commands for the same device
may end up being submitted through different queues, and when the submitted
commands include a mix of NCQ and non-NCQ commands, the problem happens without
libata being able to easily do anything about it, and not possible control
possible at the scsi layer either since the commands submitted are SCSI (not yet
translated to ATA commands) which do not have any NCQ/non-NCQ exclusion
knowledge at all. NCQ is an ATA concept unknown to the scsi and block layer.
We (Niklas and I) are trying to find a solution, but that may not be within
libata itself. It may need changes to libsas as well. Not sure yet. Still exploring.
Hello Xingui,
I send a proposed solution to this problem here:
https://lore.kernel.org/linux-ide/20241031140731.224589-4-cassel@xxxxxxxxxx/
Please test and see if it addresses your problem.
OK, thanks for following this issue and fixing it, we will verify it as
soon as possible.
Thanks.
Xingui
