set NCCL_SHM_DISABLE=1 for test_parallel_executor_profilery.py (#28484)

python/paddle/fluid/tests/unittests/test_parallel_executor_profiler.py

@@ -19,6 +19,14 @@ import numpy as np
 import paddle.fluid as fluid
 import paddle.fluid.core as core
 from paddle.fluid.tests.unittests.test_profiler import TestProfiler
+import os
+
+# NCCL 2.7 decides to use shared memory while NCCL 2.6 didn't, hence causing the error.
+# include/shm.h:28 NCCL WARN Call to posix_fallocate failed: No space left on device
+#
+# Set environment variables NCCL_SHM_DISABLE=1 to disables the Shared Memory (SHM) transports 
+# and force to use P2P which is the default transports way of NCCL2.6.
+os.environ['NCCL_SHM_DISABLE'] = str(1)
 
 
 class TestPEProfiler(TestProfiler):