>>>>> "Mike" == Mike Snitzer <snitzer@xxxxxxxxxx> writes: Mike> When I implemented dm_table_supports_discards() I consciously Mike> allowed a DM table to contain a mix of discard support. I'm now Mike> wondering where it is we benefit from that? Seems like more of a Mike> liability than anything -- so a bigger hammer approach to fixing Mike> this would be to require all targets and all devices in a DM table Mike> support discard. I think our original rationale was that since discard is only a hint it would be fine to mix and match. And at the time there seemed to be value in supporting a heterogeneous setups with say a disk drive and an SSD. Back then the SSD vendors were all busy telling us how crucial discard would be going forward. However, that turned out not to be the case and discard often causes more problems than it solves. So I'm perfectly OK with requiring all devices in a table to have the same capabilities. In many ways I think that's a cleaner approach. -- Martin K. Petersen Oracle Linux Engineering -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
