On Wed, 2017-03-08 at 22:03 +0200, Sagi Grimberg wrote: > This workqueue is used by our storage target mode ULPs > via the new CQ API. Recent observations when working > with very high-end flash storage devices reveal that > UNBOUND workqueue threads can migrate between cpu cores > and even numa nodes (although some numa locality is accounted > for). > > While this attribute can be useful in some workloads, > it does not fit in very nicely with the normal > run-to-completion model we usually use in our target-mode > ULPs and the block-mq irq<->cpu affinity facilities. > > The whole block-mq concept is that the completion will > land on the same cpu where the submission was performed. > The fact that our submitter thread is migrating cpus > can break this locality. > > We assume that as a target mode ULP, we will serve multiple > initiators/clients and we can spread the load enough without > having to use unbound kworkers. > > Also, while we're at it, expose this workqueue via sysfs which > is harmless and can be useful for debug. > > Signed-off-by: Sagi Grimberg <sagi@xxxxxxxxxxx> Thanks, applied. -- Doug Ledford <dledford@xxxxxxxxxx> GPG KeyID: B826A3330E572FDD Key fingerprint = AE6B 1BDA 122B 23B4 265B 1274 B826 A333 0E57 2FDD -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
