RE: [PATCH v2 39/49] IB/hfi1: add sysfs routines

Marciniszyn, Mike
2015-07-08T22:32:44Z

> > This sysfs entries are used by PSM2 to form packets from user space.
>
> You didn't explain what's SC and what's SC-to-VL and why PSM2 can't talk to
> the SM to query that.
>

SC stands for Service Channel and is a Fabric wide concept.

These tables are used to as to perform the following mapping:
- SL -> SC -> VL

VL is virtual lane and pertains to the link with the immediate peer and is presented in the packets sent from PSM2.

The current design uses the core supported sysfs extensions to create driver specific files in the infiniband class as did qib and PSM1.

> >> >> +HFI1_VL2MTU_ATTR(0);

OPA has a per VL MTU, which PSM requires to form its packets correctly.

Mike