Perf top always show 0.00

[Frank Li]

I use mx6dq platform. Found below problem.

Run Perf top. First column always 0, but order look like correct.

   0.00%  perf          [.] 0x00049420
     0.00%  [kernel]      [k] kallsyms_expand_symbol.constprop.5
     0.00%  [kernel]      [k] vsnprintf
     0.00%  [kernel]      [k] arch_cpu_idle
     0.00%  [kernel]      [k] format_decode
     0.00%  [kernel]      [k] number.isra.2
     0.00%  libc-2.19.so  [.] strstr
     0.00%  libc-2.19.so  [.] 0x00072498
     0.00%  libc-2.19.so  [.] memchr
     0.00%  [kernel]      [k] _raw_spin_unlock_irqrestore
     0.00%  [kernel]      [k] string.isra.4
     0.00%  [kernel]      [k] strnlen
     0.00%  libc-2.19.so  [.] getdelim
     0.00%  libc-2.19.so  [.] memcpy
     0.00%  [kernel]      [k] lock_acquire
     0.00%  libc-2.19.so  [.] strchr
     0.00%  libc-2.19.so  [.] strcmp
     0.00%  [kernel]      [k] _raw_spin_unlock_irq
     0.00%  libc-2.19.so  [.] __libc_calloc
     0.00%  libc-2.19.so  [.] _IO_feof
     0.00%  [kernel]      [k] pointer.isra.15