1 / 6

Missing info

Missing info. Adam Moody and Torsten Hoefler Chicago 3/28/11. Where is MPI_Info used?. Functions that take MPI_Info DIST_GRAPH_CREATE_ADJACENT, DIST_GRAPH_CREATE ALLOC_MEM COMM_SPAWN, COMM_SPAWN_MULTIPLE OPEN_PORT, COMM_ACCEPT, COMM_CONNECT, PUBLISH_NAME, UNPUBLISH_NAME, LOOKUP_NAME

vivi
Download Presentation

Missing info

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Missing info Adam Moody and TorstenHoefler Chicago 3/28/11

  2. Where is MPI_Info used? • Functions that take MPI_Info • DIST_GRAPH_CREATE_ADJACENT, DIST_GRAPH_CREATE • ALLOC_MEM • COMM_SPAWN, COMM_SPAWN_MULTIPLE • OPEN_PORT, COMM_ACCEPT, COMM_CONNECT, PUBLISH_NAME, UNPUBLISH_NAME, LOOKUP_NAME • WIN_CREATE • FILE_OPEN, FILE_DELETE, FILE_SET_INFO, FILE_GET_INFO, FILE_SET_VIEW • Relevant sections • Chapter 9: Info Object • Section 13.2.8: File Info • A.1.5: Info Keys • A.1.6: Info Values

  3. Some hints are assertions • Some MPI_Info hints are assertions; MPI can crash if app lies, e.g., • no_locks– MPI can break if no_locks is specified but app uses MPI_Win_lock anyway. • Possible assertions for communicators • no_any_source– simplifies matching • no_any_tag – simplifies matching • free_strict – no reference counting • no_reduction_determinism – optimized colls • no_heterogeneity – simpler DT handling • no_send_cancel – simpler send handling • match_packed – MPI_PACKED in send only matches MPI_PACKED in recv • strict_topology – only send pt-2-pt to neighbors in topology

  4. #4 is needed already – what if app sets no_locks on window and then passes window to library? • #2 will be needed if we ever define any assertions on comms. • Thoughts on #1 and #3?

  5. Discussion points • Copy info on COMM_DUP? • Intent of dup is to provide identical comm for library. • We copy attributes, topology, and error handler. • On other hand, this may inhibit library (e.g., strict_topology). • FILE_GET_INFO returns all hints in use, including those not set by user. Want to do the same for comms and windows? • Once set on file, hints cannot be unset, p398, line 29 • “When an info object that specifies a subset of valid hints is passed to MPI_FILE_SET_VIEW or MPI_FILE_SET_INFO, there will be no effect on previously set or defaulted hints that the info does not specify.”

  6. Suggested proposal • MPI_COMM_GET_INFO • MPI_WIN_GET_INFO • MPI_COMM_SET_INFO • May ignore hints that otherwise can be set at creation • MPI_WIN_SET_INFO • May ignore hints that otherwise can be set at creation • MPI_COMM_DUP(incomm, outcomm) • Duplicates info from incomm • MPI_COMM_DUP_INFO(incomm, outcomm, info) • Overwrites info from incomm

More Related