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. Kind regards, Niklas
