[upc-users] Max Local Segment Size is too small
dmajumde at mail.uh.edu
Fri Aug 19 14:03:49 PDT 2011
I am using GASNet for implementing Coarray Fortran runtime. I find the
maximum memory that can be attached (gasnet_attach) to be inadequate. Is
there a way to attach more memory using 'fast' or 'large' configuration
without sacrificing performance?
Function gasnet_getMaxLocalSegmentSize() returns 2145382400 (~2GB) for
both FAST and LARGE configuration.
I am using an Opteron system with 64GB memory on each node. Each node
has 48 cores (8 NUMA nodes, 4 sockets).
I tried using:
2 nodes, each with 1 process, using Infiniband conduit.
1 node ( 2 procs) using SMP conduit.
I got the same max segment size for both cases.
In UPC, I can use 5GB (by using shared-heap option in upcrun). I built
UPC with GASNet 'fast'. How does UPC attach more memory?
University of Houston
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