code: def read_direct(fd, sz):
      with Timing("mmap: ", lambda x: f", {sz/x:.2f} GB/s"):
          buf = mmap.mmap(
              -1, sz, flags=mmap.MAP_SHARED | mmap.MAP_POPULATE
          )
      with Timing("read: ", lambda x: f", {sz/x:.2f} GB/s"):
          ret = libc.read(fd, from_mv(buf), sz)
      assert ret == sz
  
file_path: tinygrad/extra/disk_read_speed.py
imports: import os, ctypes, ctypes.util, io, mmap
  from tinygrad import Tensor, dtypes, Device
  from tinygrad.helpers import Timing, from_mv
  from tinygrad.runtime.ops_hip import HIPDevice
label_desc: Use image node_id 1 for calling a global function with example usage: read_direct(fd, sz) without return types