[BUG] [MG] coo2csr failure on 64GB input

[afender]

Describe the bug

mem free: 3.15815e+10  mem total: 3.40583e+10  mem used: 2.4768e+09
  mem free: 3.10876e+10  mem total: 3.40583e+10  mem used: 2.97068e+09
  mem free: 3.10876e+10  mem total: 3.40583e+10  mem used: 2.97068e+09
  mem free: 3.10876e+10  mem total: 3.40583e+10  mem used: 2.97068e+09
  mem free: 3.10876e+10  mem total: 3.40583e+10  mem used: 2.97068e+09
  mem free: 3.10876e+10  mem total: 3.40583e+10  mem used: 2.97068e+09
  mem free: 3.10876e+10  mem total: 3.40583e+10  mem used: 2.97068e+09
  mem free: 3.10247e+10  mem total: 3.40583e+10  mem used: 3.0336e+09
  mem free: 3.09492e+10  mem total: 3.40583e+10  mem used: 3.10909e+09
  mem free: 3.10247e+10  mem total: 3.40583e+10  mem used: 3.0336e+09
  mem free: 3.10876e+10  mem total: 3.40583e+10  mem used: 2.97068e+09
  mem free: 3.10876e+10  mem total: 3.40583e+10  mem used: 2.97068e+09
  mem free: 3.10247e+10  mem total: 3.40583e+10  mem used: 3.0336e+09
  mem free: 3.10876e+10  mem total: 3.40583e+10  mem used: 2.97068e+09
  mem free: 3.05308e+10  mem total: 3.40583e+10  mem used: 3.52748e+09
  mem free: 3.09618e+10  mem total: 3.40583e+10  mem used: 3.09651e+09
myRowCount: 0
myRowCount: 247029006
myRowCount: 247028939
myRowCount: 247028972
myRowCount: -1976231961
myRowCount: 0
myRowCount: -342503438
myRowCount: 247028973
myRowCount: 247029038
myRowCount: 0
myRowCount: 0
myRowCount: 247029005
myRowCount: 0
myRowCount: 247029019
myRowCount: 0
myRowCount: 247029009terminate called after throwing an instance of 'std::runtime_error'
terminate called recursively
  what():  ERROR: RMM runtime call  RMM_ALLOC((&cooRowNew), (sizeof(idx_t) * myRowCount), (nullptr))out of memory
/home/nfs/iroy/anaconda3/envs/cugraph_env/lib/python3.7/multiprocessing/semaphore_tracker.py:144: UserWarning: semaphore_tracker: There appear to be 1 leaked semaphores to clean up at shutdown
  len(cache))
distributed.nanny - WARNING - Worker process 70692 was killed by signal 6
distributed.nanny - WARNING - Restarting worker

To Reproduce
run hibench test on bigdatax2 on a dgx in the lab (disable Nx comparison)

[afender]

closed by #410