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. - Fab _______________________________________________ openib-general mailing list [email protected] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
