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Threads WG Meeting 03 20 2018

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Manjunath Gorentla Venkata edited this page Oct 2, 2018 · 1 revision

(Thanks Swaroop for the meeting minutes)

Attendees:

  • Manjunath
  • Aurelein
  • Brian
  • Dave Ozog
  • Jim Dinan
  • Khaled
  • Naveen
  • Tony
  • Swaroop
  • Swen Bohem

Swen Bohem presented proposal for non-blocking RMA through Merged request

Discussion that followed:

Q: Do we track all RMA operations ? A: Usually every operations have a descriptor, this API forms a lightweight wrapper around it. Comment: For Portals using descriptors causes performance degradation.

Q: Contrasting with context functionality vs. merged requests A: There is an overlap in context and merged requests. But merged requests allows logical segregation of operations.

Q: How to check progress?
A: Not part of current proposal. Suggestion: Not create descriptor at start but at point of progress check at origin, link requests and do actual data transfer. Counter: Would limit overlap.

Comment: There is no way of expressing ordering Counter: It is equivalent to having multiple merged handles.

Q: How does this interact with context ? A: Orthogonal concepts. Can reside agnostic to each other. Comment: 3 ways - current (agnostic), create on context, provide context in communication.

Q: How does merged request choose resources ? A: Can use default context. Counter: Then fence and quiet will affect them. Comment: It is not required but not incorrect to have ordering.

Concern: If context is specified in nbe operation and are using merged request —> merged requests spanning multiple contexts.

Q: Can we express priority between requests/contexts ? Comment: For contexts - User can set an option on the context and implementation can guarantee it by assigning higher fabric level QoS. Can have multiple contexts with same QoS.

—— Straw Poll:

  • Op1: Work on this proposal to clarify semantics and interactions with context.
  • Rice (Max), UTK (Aurelein ), Intel (Dave), Cray (Naveen), SBU (Tony), ORNL (Manju)
  • Op2: Trim down proposal — only RMA with handles.
  • Intel (Jim), AMD (Khaled)
  • Op3: No proposal.
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