Messages in this thread | | | Subject | Re: [PATCH V7 4/6] blk-mq: introduce .get_budget and .put_budget in blk_mq_ops | From | Bart Van Assche <> | Date | Tue, 17 Oct 2017 11:09:15 -0700 |
| |
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.
| |