[EMAIL PROTECTED] wrote: > Hi Rick, > > On 4/19/06, Richard Frank <[EMAIL PROTECTED]> wrote: >> Some application level protocols - require higher QoS levels than >> others - for various communication and I/O operations. >> >> For example, cluster inter-node health msgs have fixed latency >> requirements that if exceeded may result in unexpected node removals >> from the cluster. >> >> Are there any mechanisms available to the client process to manage >> the QoS level for the various supported ULPs >> (SDP,TCP,UDP,RDS,SRP,iSER,etc) either at the ULP level or some >> combination of process and ULP - or perhaps even at the connection >> level ? > > IB has the concept of Virtual Lanes (VL) at the hardware > level, and Service Levels (SL) at the software level. There > are always 16 SLs that map to however many VLs are supported > by the hardware. IB hardware has at a minimum 2 VLs - VL0 > and VL15, the latter being reserved for QP0 management > traffic (for configuring the fabric). > > A module parameter to each ULP could assign it an SL to > achieve the prioritization you are looking for. There could > even be a limit to the SLs available to user-mode, enforced > by the kernel for connected QPs, though I don't know if the same can > be said for UD QPs. > > The SM configures the SL to VL mappings for each node, which > causes somewhat of a problem - you don't know exactly what VL > any particular SL is mapped to. Hardware that doesn't > support all VLs could have multiple SLs mapped to any given > VL. This means that if you pick SL0 for SRP and SL1 for > IPoIB, both of those *may* map to VL0. >
Any given fabric will have solutions to this. The question is how the user of OpenFabrics ties their QPs and connections to the fabric-specific traffic management. _______________________________________________ openib-general mailing list openib-general@openib.org http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general