On 10/16/17 23:38, Hannes Reinecke wrote:
Again, these are just some pre-defined values to avoid I/O starvation when having several LUNs. _if_ we can guarantee I/O fairness between several (hundreds!) devices all sharing the same tagspace we wouldn't need these variables.
I think we already have two mechanisms for guaranteeing I/O fairness: * Scsi_Host.starved_list for both the legacy SCSI core and scsi-mq. * For scsi-mq, the active_queues counter in the blk-mq core. See also hctx_may_queue(). Bart.