After CPU profiling using gproftools (google profiler) it show some function name as hexadecimal values.
According to last comment of https://groups.google.com/forum/#!topic/google-perftools/7sdO7wrPUpE the problem looks like caused by ASLR But I did not understand why few function names are hexadecimal value while other are normal.
Sample Output of profiling.
16 0.40% 86.80% 16 0.40% 00007f05e018bc5d
16 0.40% 87.20% 36 0.90% _IO_file_xsgetn
16 0.40% 87.60% 16 0.40% __memcpy_sse2
16 0.40% 88.00% 16 0.40% __tls_get_addr
15 0.40% 88.40% 15 0.40% __GI___libc_free
15 0.40% 88.70% 15 0.40% __GI_strlen