Add comment on nogil
@@ -218,6 +218,9 @@ cdef class NcclCommunicator:
raise RuntimeError("ncclCommGetAsyncError is not available"
" in this version")
cdef ncclResult_t asyncError = ncclSuccess
+ # Releasing GIL as the function *might* block in future and
+ # this won't be a hot code path. At least in NCCL 2.4 it does
+ # not block so far.
with nogil:
result = ncclCommGetAsyncError(self._comm, &asyncError)
check_status(asyncError)
