On 2020/05/14 11:20, Martin K. Petersen wrote: > > Damien, > >> Indeed. It is an NVMe M.2 consumer grade SSD. Nothing fancy. If you >> look at nvme/host/core.c nvme_update_disk_info(), you will see that >> io_opt is set to the block size... This is probably abusing this >> limit. So I guess the most elegant fix may be to have nvme stop doing >> that ? > > Yeah, I'd prefer for io_opt to only be set if the device actually > reports NOWS. Sent a patch :) > > The purpose of io_min is to be the preferred lower I/O size > boundary. One should not submit I/Os smaller than this. > > And io_opt is the preferred upper boundary for I/Os. One should not > issue I/Os larger than this value. Setting io_opt to the logical block > size kind of defeats that intent. > > That said, we should probably handle the case where the pbs gets scaled > up but io_opt doesn't more gracefully. Yes. Will look at that too. Thanks ! > -- Damien Le Moal Western Digital Research -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
