8

I have a LeMaker HiKey development board. I purchased it for testing a couple of libraries on ARM64 cpu architecture. The board provides two Cortex-A53 processors, provides eight cores, and uses Linaro Linux:

$ uname -a
Linux hikey 3.18.0-linaro-hikey #1 SMP PREEMPT Mon Nov 30 00:11:03 UTC 2015
aarch64 GNU/Linux

I observed the self tests are running a little slower than expected, so I'm mildly investigating it. I also noticed a cat of /proc/cpuinfo is returning something that does not look quite right, but I'm not sure if its cause for concern. It does not look quite right to me because I used to seeing cpu information present for each core (something like shown in Number of processors in /proc/cpuinfo).

Does the output of /proc/cpuinfo indicate a problem with the board or its configuration? Or is this output expected with some dev boards?

ARM Cortex A53 (octa-core):

$ cat /proc/cpuinfo 
Processor   : AArch64 Processor rev 3 (aarch64)
processor   : 0
processor   : 1
processor   : 2
processor   : 3
processor   : 4
processor   : 5
processor   : 6
processor   : 7
Features    : fp asimd evtstrm aes pmull sha1 sha2 crc32 
CPU implementer : 0x41
CPU architecture: AArch64
CPU variant : 0x0
CPU part    : 0xd03
CPU revision    : 3

Hardware    : HiKey Development Board
Community
  • 1

1 Answers1

8

This is the expected output to Arm based processors. All Serialized cores are shown in list with line breaks instead of separated processors. Features are evaluated by cpuinfo code, and only show if all cores support them

         /*
          * Mismatched CPU features are a recipe for disaster. Don't even
          * pretend to support them.
          */
         WARN_TAINT_ONCE(diff, TAINT_CPU_OUT_OF_SPEC,
                         "Unsupported CPU feature variation.");

The other variables are:

  • CPU implementer: Your code means ARM;
  • CPU architecture: AArch64 means 64 bit ARM board:
  • CPU variant : Indicates the variant number of the processor, or "major revision". Yours is zero.
  • CPU part: Part number. 0xd03 indicates Cortex-A53 processor.
  • CPU revision: Indicates patch release or "minor revision". 3, in your case
  • Hardware : HiKey Development Board is self explanatory

If you want to check your processor max clock, just type cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq. To check the current clock dmidecode | grep "Current Speed" should do the trick.

Another thing that could impact the performance of your processor is the cpu governor you are using. Maybe setting the performance one could be better for your needs:

cpupower frequency-set -g performance

Documentation:

Community
  • 1