I'm monitoring the performance of an ARM-based embedded device which runs poky linux distro (from Yocto project) which contains OpenEmbedded build system. I need to get the MHz (CPU cycles) consumption and the RAM used for any process that runs on the system. Though top utility allows me to see the CPU % used (which allows me to estimate CPU MHz in turn), it just gives the virtual memory size (VSZ) used by the process but no physical memory used.

Is there a way I can get this information I need?


I think "cycles" is generally pretty meaningless (it was when cpu's had no cache and 1 core). What is more useful is the "idle" time -- and how much cpu individual processes are consuming (and domain experience to understand "what's reasonable".

htop or top is useful -- you may also want to look at /proc/loadavg and /proc/meminfo.

  • I agree that it is meaningless as far as PCs are concerned. But, when working on performance tuning of embedded systems, whose max processor speed is in MHz, it is quite important. I'm aware of /proc/meminfo and /proc/loadavg. Both give the overall RAM consumed and CPU Utilization, which is actually not what I am looking for. I need the same for each individual process. – skrowten_hermit Mar 22 '16 at 5:54

Here is a list that explains what each column means.

  • PID: A process’s process ID number.
  • USER: The process’s owner.
  • PR: The process’s priority. The lower the number, the higher the
  • NI: The nice value of the process, which affects its priority.
  • VIRT: How much virtual memory the process is using.
  • RES: How much physical RAM the process is using, measured in kilobytes.
  • SHR: How much shared memory the process is using.
  • S: The current status of the process (zombied, sleeping, running, uninterruptedly sleeping, or traced).
  • %CPU: The percentage of the processor time used by the process.
  • %MEM: The percentage of physical RAM used by the process.
  • TIME+: How much processor time the process has used.
  • COMMAND: The name of the command that started the process.

Following the comment of Gilles (htop doesn't show more information than top does, it only shows it in a nicer way), which I don't agree, in my distro htop shows far more information than top:

htop vs top in Arago linux

  • I am aware of free, but I need the process wise RAM consumption. free doesn't give that, does it? – skrowten_hermit Mar 17 '16 at 11:10
  • Sorry...didn't paid enough attention to your question... – marc Mar 17 '16 at 11:21
  • The problem is this particular distribution doesn't come with htop utility. :( – skrowten_hermit Mar 17 '16 at 11:27
  • which distribution is it? – marc Mar 17 '16 at 14:35
  • It's poky linux distro (from Yocto project) which contains OpenEmbedded build system. – skrowten_hermit Mar 17 '16 at 14:42

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