A Questions about asynchronous saving

[JOjoker-world]

`Fsync the file after writing to gaurantee persistence

Call this in a new process to perform in bgk
"""
def _serialize_and_persist(
self,
filepath,
snapshot,
active_snapshot,
lock,
linkpath=None,
iter_chk = None,
epoch_chk = None,
overwrite = True):
print("[{}] START ASYNC".format(time.time()))

with lock:
	if active_snapshot.value == 0:
		self.logger.error("Cannot persist. Empty snapshot")
		return
#Create new stream
s = torch.cuda.Stream()
torch.cuda.stream(s)

#print("Saving : {}".format(filepath))
torch.save(snapshot, filepath)
#print("Saved : {}".format(filepath))
# Clear the snapshot.
with lock:
	active_snapshot.value = 0

# Ensure its persisted
f = open(filepath, 'a+')
os.fsync(f.fileno())
f.close()

update_stats(
		filepath,
		iter_chk=iter_chk,
		overwrite=overwrite,
		epoch_chk = epoch_chk,
		linkpath=linkpath)
print("[{}] END ASYNC".format(time.time()))`

In this code segment:
# Create new stream s = torch.cuda.Stream() torch.cuda.stream(s) torch.save(snapshot, filepath)
I tested it and found that it did not achieve the overlapping of computation and saving. It seems that CheckFreq did not call the entire function. Could you please advise if this function is feasible?