[OMPI devel] Loadbalancing
I added a new "loadbalance" feature to OMPI today in r18252. Brief summary: adding --loadbalance to the mpirun cmd line will cause the round-robin mapper to balance your specified #procs across the available nodes. More detail: Several users had noted that mapping byslot always caused us to preferentially load the first nodes in an allocation, potentially leaving other nodes unused. If they mapped bynode, of course, this wouldn't happen - but then they were forced to a specific rank-to-node relationship. What they wanted was to have the ranks numbered byslot, but to have the ppn balanced across the entire allocation. This is now supported via the --loadbalance cmd line option. Here is an example of its affect (again, remember that loadbalance only impacts mapping byslot): no-lb lb bynode node0: 0,1,2,30,1,2 0,3,6 node1: 4,5,6 3,4 1,4 node2: 5,6 2,5 As you can see, the affect of --loadbalance is to balance the ppn across all the available nodes while retaining byslot rank associations. In this case, instead of leaving one node unused, we take advantage of all available resources. Hope this proves helpful Ralph
Re: [OMPI devel] Communication problem
I'm surprised that it takes "a minute" to fail to find IB -- usually the search and failure is more-or-less instantaneous. Can you send all the information listed here? http://www.open-mpi.org/community/help/ On Apr 23, 2008, at 5:55 AM, Ziv Mhabary wrote: Hi, When im tring to run a code, its first looking for Infiniband communication,i dont have infiniband in my cluster, so after a minute its start to look for the ethernet and then its work. how can i change my default communication? i want it to search for the ethernet first. Thanks! Ziv. ___ devel mailing list de...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/devel -- Jeff Squyres Cisco Systems
[OMPI devel] Merging in the CPC work
As we discussed yesterday, I have started the merge from the /tmp- public/openib-cpc2 branch. "oob" is currently the default. Unfortunately, it caused quite a few conflicts when I merged with the trunk, so I created a new temp branch and put all the work there: /tmp- public/openib-cpc3. Could all the IB and iWARP vendors and any other interested parties please try this branch before we bring it back to the trunk? Please test all functionality that you care about -- XRC, etc. I'd like to bring it back to the trunk COB Thursday. Please let me know if this is too soon. You can force the selection of a different CPC with the btl_openib_cpc_include MCA param: mpirun --mca btl_openib_cpc_include oob ... mpirun --mca btl_openib_cpc_include xoob ... mpirun --mca btl_openib_cpc_include rdma_cm ... mpirun --mca btl_openib_cpc_include ibcm ... You might want to concentrate on testing oob and xoob to ensure that we didn't cause any regressions. The ibcm and rdma_cm CPCs probably still have some rough edges (and the IBCM package in OFED itself may not be 100% -- that's one of the things we're evaluating. It's known to not install properly on RHEL4U4, for example -- you have to manually mknod and chmod a device in /dev/infiniband for every HCA in the host). Thanks. -- Jeff Squyres Cisco Systems
[OMPI devel] Communication problem
Hi, When im tring to run a code, its first looking for Infiniband communication,i dont have infiniband in my cluster, so after a minute its start to look for the ethernet and then its work. how can i change my default communication? i want it to search for the ethernet first. Thanks! Ziv.
