On Wed, Feb 06, 2019 at 09:21:40AM +0000, John Garry wrote: > On 05/02/2019 18:23, Christoph Hellwig wrote: > > On Tue, Feb 05, 2019 at 03:09:28PM +0000, John Garry wrote: > > > For SCSI devices, unfortunately not all IO sent to the HW originates from > > > blk-mq or any other single entity. > > > > Where else would SCSI I/O originate from? > > Please note that I was referring to other management IO, like SAS SMP, TMFs, > and other proprietary commands which the driver may generate for the HBA - > https://marc.info/?l=linux-scsi&m=154831889001973&w=2 discusses some of them > also. >
Especially the TMFs send via SCSI EH are a bit of a pain I guess, because they are entirely managed by the device drivers, but depending on the device driver they might not even qualify for the problem Hannes is seeing. -- With Best Regards, Benjamin Block / Linux on IBM Z Kernel Development IBM Systems & Technology Group / IBM Deutschland Research & Development GmbH Vorsitz. AufsR.: Matthias Hartmann / Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen / Registergericht: AmtsG Stuttgart, HRB 243294
