Remove thread local thrust::sort (thrust::sort with the execution policy thrust::seq) from copy_v_transform_reduce_key_aggregated_out_nbr

[seunghwak]

thrust::sort(thrust::seq, ....) does not work with arbitrary large input data size and this call can fail if the array size to locally sort is large. This code replaces many thread local sort with one thrust::sort call from host.

[seunghwak]

@ChuckHastings This fixes the error in thrust::sort(thrust::seq, ...) calls.

If I replace

karate.mtx with hollywood.mtx in
https://github.com/rapidsai/cugraph/blob/branch-21.06/cpp/tests/community/mg_louvain_test.cpp#L234

and run ./tests/MG_LOUVAIN_TEST

I got the following error.

(cuda112-cugraph) seunghwak@seunghwak-linux:~/RAPIDS/development/cugraph/cpp/build$ ./tests/MG_LOUVAIN_TEST 
[==========] Running 1 test from 1 test suite.
[----------] Global test environment set-up.
[----------] 1 test from simple_test/Louvain_MG_Testfixture
[ RUN      ] simple_test/Louvain_MG_Testfixture.CheckInt32Int32Float/0
/home/seunghwak/RAPIDS/development/cugraph/cpp/tests/community/mg_louvain_test.cpp:160: Failure
Value of: cugraph::test::compare_renumbered_vectors( handle, d_clustering_v, d_dendrogram_gathered_v)
  Actual: false
Expected: true
Google Test trace:
/home/seunghwak/RAPIDS/development/cugraph/cpp/tests/community/mg_louvain_test.cpp:210: compare modularity input: /datasets/test/datasets/hollywood.mtx
/home/seunghwak/RAPIDS/development/cugraph/cpp/tests/community/mg_louvain_test.cpp:160: Failure
Value of: cugraph::test::compare_renumbered_vectors( handle, d_clustering_v, d_dendrogram_gathered_v)
  Actual: false
Expected: true
Google Test trace:
/home/seunghwak/RAPIDS/development/cugraph/cpp/tests/community/mg_louvain_test.cpp:210: compare modularity input: /datasets/test/datasets/hollywood.mtx
/home/seunghwak/RAPIDS/development/cugraph/cpp/tests/community/mg_louvain_test.cpp:38: Failure
Expected equality of these values:
  mg_modularity
    Which is: 0.57750976
  sg_modularity
    Which is: 0.57050145
Google Test trace:
/home/seunghwak/RAPIDS/development/cugraph/cpp/tests/community/mg_louvain_test.cpp:210: compare modularity input: /datasets/test/datasets/hollywood.mtx
[  FAILED  ] simple_test/Louvain_MG_Testfixture.CheckInt32Int32Float/0, where GetParam() = 56-byte object <60-FD C9-96 59-55 00-00 25-00 00-00 00-00 00-00 25-00 00-00 00-00 00-00 02-00 00-00 6A-20 00-00 01-20 00-00 00-00 00-00 64-00 00-00 00-00 00-00 00-00 00-00 00-00 F0-3F> (56353 ms)
[----------] 1 test from simple_test/Louvain_MG_Testfixture (56353 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test suite ran. (56353 ms total)
[  PASSED  ] 0 tests.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] simple_test/Louvain_MG_Testfixture.CheckInt32Int32Float/0, where GetParam() = 56-byte object <60-FD C9-96 59-55 00-00 25-00 00-00 00-00 00-00 25-00 00-00 00-00 00-00 02-00 00-00 6A-20 00-00 01-20 00-00 00-00 00-00 64-00 00-00 00-00 00-00 00-00 00-00 00-00 F0-3F>

 1 FAILED TEST
(cuda112-cugraph) seunghwak@seunghwak-linux:~/RAPIDS/development/cugraph/cpp/build$ 

[ChuckHastings]

Tested this with some other changes (will be in a separate PR) and got Louvain working on larger graphs.

[codecov-commenter]

Codecov Report

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@@               Coverage Diff               @@
##             branch-21.06    #1627   +/-   ##
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  Misses                  ?     1396           
  Partials                ?        0           

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[BradReesWork]

@gpucibot merge