Add xla_dump_dir in the config file.

Author: qinyiyan

configs/sample_benchmark_collectives.yaml

@@ -4,16 +4,19 @@ benchmarks:
  - {matrix_dim_range: {start: 1024, end: 20000, increase_by: 1024}, dtype: "bfloat16", dcn_size_range: 1, ici_size_range: 4}
  trace_dir: "/tmp/microbenchmarks/collectives"
  csv_path: "/tmp/microbenchmarks/collectives"
+ xla_dump_dir: "/tmp/microbenchmarks/collective/hlo_graphs"
 - benchmark_name: all_gather
  benchmark_sweep_params:
  - {matrix_dim_range: {start: 1024, end: 20000, increase_by: 1024}, dtype: "bfloat16", dcn_size_range: 1, ici_size_range: 4}
  trace_dir: "/tmp/microbenchmarks/collectives"
  csv_path: "/tmp/microbenchmarks/collectives"
+ xla_dump_dir: "/tmp/microbenchmarks/collective/hlo_graphs"
 - benchmark_name: psum
  benchmark_sweep_params:
  - {matrix_dim_range: {start: 1024, end: 20000, increase_by: 1024}, dtype: "bfloat16", dcn_size_range: 1, ici_size_range: 4}
  trace_dir: "/tmp/microbenchmarks/collectives"
  csv_path: "/tmp/microbenchmarks/collectives"
+ xla_dump_dir: "/tmp/microbenchmarks/collective/hlo_graphs"
 - benchmark_name: psum_scatter
  benchmark_sweep_params:
  - {matrix_dim_range: {start: 1024, end: 20000, increase_by: 1024}, dtype: "bfloat16", dcn_size_range: 1, ici_size_range: 4}