On Tue, Mar 23, 2021 at 05:52:33PM +1000, Erwin van Londen wrote: > Hello All, > > Just wondering if there were any plans to incorporate FPIN > congestion/latency notifications in dm-multipath to disperse IO over > non-affected paths. > For whats worth, general support in Kernel for a new path state in answer to existing FPIN notifications was added earlier this year: https://lore.kernel.org/linux-scsi/1609969748-17684-1-git-send-email-muneendra.kumar@xxxxxxxxxxxx/T/ But this only adds a new port-state and support of it for one particular driver (lpfc). Not aware of any other driver supporting this new state yet, but I might have missed it. Also, the port-state is not set in kernel, but has to be set by something external, unlike with RSCNs, where we set the state in the kernel. What it does, once a path is set into 'Marginal' state, is to not retry commands on the same shaky path, once it already failed one time already. As far as dm-multipath is concerned, I asked that as well when this patch series was developed: https://lore.kernel.org/linux-scsi/20201002162633.GA8365@t480-pf1aa2c2/ Hannes answered that in the thread: https://lore.kernel.org/linux-scsi/ca995d96-608b-39b9-8ded-4a6dd7598660@xxxxxxx/ Not sure what happened in between, didn't see anything on the mpath topic yet. -- Best Regards, Benjamin Block / Linux on IBM Z Kernel Development / IBM Systems IBM Deutschland Research & Development GmbH / https://www.ibm.com/privacy Vorsitz. AufsR.: Gregor Pillen / Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen / Registergericht: AmtsG Stuttgart, HRB 243294 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel
