code: def pytorch_log_fw_bw(x):
      y = torch.norm(torch.log_softmax(x, dim=-1))
      y.backward()
  
file_path: xformers/xformers/benchmarks/benchmark_triton_softmax.py
imports: import torch
  from xformers.benchmarks.utils import TestCase, bench_functions
  from xformers.triton.softmax import log_softmax
  from xformers.triton.softmax import softmax
label_desc: Use image node_id 5 for calling a global function with example usage: pytorch_log_fw_bw(x) without return types