How to get overall CPU usage (e.g. 57%) on Linux [closed]
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I am wondering how you can get the system CPU usage and present it in percent using bash, for example. Sample output:
Reopening I don’t understand why this was ruled as off-topic, could the ones who closed it please care to elaborate?
My understanding of /proc/stat is very limited, but this one-liner works good enough for me: cat <(grep 'cpu ' /proc/stat) <(sleep 1 && grep 'cpu ' /proc/stat) | awk -v '
6 Answers 6
Take a look at cat /proc/stat
EDIT please read comments before copy-paste this or using this for any serious work. This was not tested nor used, it’s an idea for people who do not want to install a utility or for something that works in any distribution. Some people think you can «apt-get install» anything.
NOTE: this is not the current CPU usage, but the overall CPU usage in all the cores since the system bootup. This could be very different from the current CPU usage. To get the current value top (or similar tool) must be used.
Current CPU usage can be potentially calculated with:
awk ' else print ($2+$4-u1) * 100 / (t-t1) "%"; >' \ <(grep 'cpu ' /proc/stat) <(sleep 1;grep 'cpu ' /proc/stat) But you have to install mpstat like you recommend above. Many people don't have that flexibility. cat /proc/stat then pipe is much easier than mpstat you recommend.
system + user + idle = 100%. So maybe something like: grep 'cpu ' /proc/stat | awk ' END '
I think that this solution doesn't show the current CPU load but the average cpu load since the CPU started.
@jlliagre, yes that's right. To calculate the CURRENT cpu usage not average, you will need to take $1 value then delay then take $1 value and see the difference. That's the current cpu usage.
top -bn1 | grep "Cpu(s)" | \ sed "s/.*, *\([0-9.]*\)%* id.*/\1/" | \ awk '' A more accurate result is given when I use top -bn2 , but it takes a long time. From what I've read, this seems to be the only way to get an accurate result.
The command in this answer appears to be written for systems where top -v returns procps-ng (e.g., Fedora). There's also procps , found on, e.g., Ubuntu and CentOS, where the command doesn't work (always indicates 100%, because parsing fails due to the line with the CPU figures being formatted differently). Here's a version that works with both implementations: top -b -n2 -p 1 | fgrep "Cpu(s)" | tail -1 | awk -F'id,' -v prefix="$prefix" '< split($1, vs, ","); v=vs[length(vs)]; sub("%", "", v); printf "%s%.1f%%\n", prefix, 100 - v >'
Side note: on OSX, use the following: top -l 2 -n 0 -F | egrep -o ' \d*\.\d+% idle' | tail -1 | awk -F% -v prefix="$prefix" '< printf "%s%.1f%%\n", prefix, 100 - $1 >' .
Try mpstat from the sysstat package
> sudo apt-get install sysstat Linux 3.0.0-13-generic (ws025) 02/10/2012 _x86_64_ (2 CPU) 03:33:26 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle 03:33:26 PM all 2.39 0.04 0.19 0.34 0.00 0.01 0.00 0.00 97.03 Then some cut or grep to parse the info you need:
mpstat | grep -A 5 "%idle" | tail -n 1 | awk -F " " ''a I'd change the awk part to: awk -F " " '
@jordanm All truths; I was more voting it up because it works. I'd do this, personally: mpstat | awk '$12 ~ /[0-9.]+/ < print 100 - $12 >'
Might as well throw up an actual response with my solution, which was inspired by Peter Liljenberg's:
This will use awk to print out 100 minus the 12th field (idle), with a percentage sign after it. awk will only do this for a line where the 12th field has numbers and dots only ( $12 ~ /8+/ ).
You can also average five samples, one second apart:
$ mpstat 1 5 | tee /dev/tty | awk 'END' Its better to run "mpstat 2 1 |. " so that it shows stats for the last 1 second. Otherwise, by default, mpstat shows stats since beginning and that does not change much as time progresses
@Sarang Thank you so much!! Finally I can get the results that conky is displaying as well. Unfortunately, this line is VERY slow, almost taking up to one whole second to execute.
@syntaxerror It takes exactly 2 seconds because if you look at the command help you see that the first argument is that it's the interval but it only executes once because of the second argument so it waits 2 full seconds until it returns the result.
Question is closed, so added my (similar) answer to yours 🙂 Hope you don't mind. Like you, I was inspired by Peter Liljenberg's answer.
EDITED: I noticed that in another user's reply %idle was field 12 instead of field 11. The awk has been updated to account for the %idle field being variable.
This should get you the desired output:
mpstat | awk '$3 ~ /CPU/ < for(i=1;i<=NF;i++) < if ($i ~ /%idle/) field=i >> $3 ~ /all/ < print 100 - $field >' If you want a simple integer rounding, you can use printf:
mpstat | awk '$3 ~ /CPU/ < for(i=1;i<=NF;i++) < if ($i ~ /%idle/) field=i >> $3 ~ /all/ < printf("%d%%",100 - $field) >' mpstat 1 1 | awk '$3 ~ /CPU/ < for(i=1;i<=NF;i++) < if ($i ~ /%idle/) field=i >> $3 ~ /all/ < printf("%d",100 - $field) >' works great for me, thanks. note the mpstat 1 1 to ensure that the cpu usage is sampled over a second
Do this to see the overall CPU usage. This calls python3 and uses the cross-platform psutil module.
printf "%b" "import psutil\nprint('<>%'.format(psutil.cpu_percent(interval=2)))" | python3 The interval=2 part says to measure the total CPU load over a blocking period of 2 seconds.
The python program it contains is this:
import psutil print('<>%'.format(psutil.cpu_percent(interval=2))) Placing time in front of the call proves it takes the specified interval time of about 2 seconds in this case. Here is the call and output:
$ time printf "%b" "import psutil\nprint('<>%'.format(psutil.cpu_percent(interval=2)))" | python3 9.5% real 0m2.127s user 0m0.119s sys 0m0.008s To view the output for individual cores as well, let's use this python program below. First, I obtain a python list (array) of "per CPU" information, then I average everything in that list to get a "total % CPU" type value. Then I print the total and the individual core percents.
import psutil cpu_percent_cores = psutil.cpu_percent(interval=2, percpu=True) avg = sum(cpu_percent_cores)/len(cpu_percent_cores) cpu_percent_total_str = ('%.2f' % avg) + '%' cpu_percent_cores_str = [('%.2f' % x) + '%' for x in cpu_percent_cores] print('Total: <>'.format(cpu_percent_total_str)) print('Individual CPUs: <>'.format(' '.join(cpu_percent_cores_str))) This can be wrapped up into an incredibly ugly 1-line bash script like this if you like. I had to be sure to use only single quotes ( '' ), NOT double quotes ( "" ) in the Python program in order to make this wrapping into a bash 1-liner work:
printf "%b" \ "\ import psutil\n\ cpu_percent_cores = psutil.cpu_percent(interval=2, percpu=True)\n\ avg = sum(cpu_percent_cores)/len(cpu_percent_cores)\n\ cpu_percent_total_str = ('%.2f' % avg) + '%'\n\ cpu_percent_cores_str = [('%.2f' % x) + '%' for x in cpu_percent_cores]\n\ print('Total: <>'.format(cpu_percent_total_str))\n\ print('Individual CPUs: <>'.format(' '.join(cpu_percent_cores_str)))\n\ " | python3 Sample output: notice that I have 8 cores, so there are 8 numbers after "Individual CPUs:":
Total: 10.15% Individual CPUs: 11.00% 8.50% 11.90% 8.50% 9.90% 7.60% 11.50% 12.30% For more information on how the psutil.cpu_percent(interval=2) python call works, see the official psutil.cpu_percent(interval=None, percpu=False) documentation here:
psutil.cpu_percent(interval=None, percpu=False)
Return a float representing the current system-wide CPU utilization as a percentage. When interval is > 0.0 compares system CPU times elapsed before and after the interval (blocking). When interval is 0.0 or None compares system CPU times elapsed since last call or module import, returning immediately. That means the first time this is called it will return a meaningless 0.0 value which you are supposed to ignore. In this case it is recommended for accuracy that this function be called with at least 0.1 seconds between calls. When percpu is True returns a list of floats representing the utilization as a percentage for each CPU. First element of the list refers to first CPU, second element to second CPU and so on. The order of the list is consistent across calls.
Warning: the first time this function is called with interval = 0.0 or None it will return a meaningless 0.0 value which you are supposed to ignore.
I use the above code in my cpu_logger.py script in my eRCaGuy_dotfiles repo.
References:
Related
How can I determine the current CPU utilization from the shell? [closed]
How can I determine the current CPU utilization from the shell in Linux? For example, I get the load average like so:
Just FYI, the load average is not the CPU usage although it may indirectly show the CPU usage. It's a number showing how many processes are out there running but waiting for resources, be it CPU or disk or something else.
can't answer the question cause it's closed but have a look at vmstat , as a bonus it works on BSDs as well.
7 Answers 7
Linux does not have any system variables that give the current CPU utilization. Instead, you have to read /proc/stat several times: each column in the cpu(n) lines gives the total CPU time, and you have to take subsequent readings of it to get percentages. See this document to find out what the various columns mean.
Because Space's answer doesn't work. It returns the average CPU usage since process start and not the current CPU usage. This answer is the correct one.
You can use top or ps commands to check the CPU usage.
using top : This will show you the cpu stats
using ps: This will show you the % cpu usage for each process.
ps -eo pcpu,pid,user,args | sort -r -k1 | less Also, you can write a small script in bash or perl to read /proc/stat and calculate the CPU usage.
We tried, and "top -b -n 1" gives very inaccurate results. "top"'s first iteration is very approximative, can give 10 percent instead of 60.
top's calculation of %CPU is different from ps's calc of %CPU. see this answer unix.stackexchange.com/questions/58539/…
The command uptime gives you load averages for the past 1, 5, and 15 minutes.
Unfortunately I need it to exit right away so I can parse the output. I'm hoping there is a file in /proc that I can read.
This will be something like this:
cpu 55366 271 17283 75381807 22953 13468 94542 0 cpu0 3374 0 2187 9462432 1393 2 665 0 cpu1 2074 12 1314 9459589 841 2 43 0 cpu2 1664 0 1109 9447191 666 1 571 0 cpu3 864 0 716 9429250 387 2 118 0 cpu4 27667 110 5553 9358851 13900 2598 21784 0 cpu5 16625 146 2861 9388654 4556 4026 24979 0 cpu6 1790 0 1836 9436782 480 3307 19623 0 cpu7 1306 0 1702 9399053 726 3529 26756 0 intr 4421041070 559 10 0 4 5 0 0 0 26 0 0 0 111 0 129692 0 0 0 0 0 95 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 369 91027 1580921706 1277926101 570026630 991666971 0 277768 0 0 0 0 0 0 0 0 0 0 0 0 0 ctxt 8097121 btime 1251365089 processes 63692 procs_running 2 procs_blocked 0