On Thu, Feb 06, 2014 at 10:38:17AM +0200, Sagi Grimberg wrote: > Both you and Nic offer a single HW queue per sdev. > I'm wandering if that should be the LLD's decision (if chooses to > use multiple queues)? > > Trying to understand how LLDs will fit in a way they exploit > multi-queue and actually > maintain multiple queues. SRP/iSER for example maintain a single > queue per connection > (or session in iSCSI). Now with multi-queue all requests of that > shost will eventually > boil-down to posting on a single queue which might transition the > bottleneck to the LLDs. > > I noticed virtio_scsi implementation is choosing a queue per command > based on current > processor id without any explicit mapping (unless I missed it). > > I guess my question is where do (or should) LLDs plug-in to this mq scheme? Just using blk-mq helps with lock contention and cacheline issues, while being conceptually simple, that's why it's the priority. See the proposal I sent before the patch series for more details. That being said if you have simple enough patches for real multiqueue support I'd be more than happy to carry them along. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
