Commands tagged cpu (19)

  • This will limit the average amount of CPU it consumes. Show Sample Output

    sudo cpulimit -p pid -l 50
    Dhinesh · 2011-11-21 08:43:57 4
  • This is useful if you have a program which doesn't work well with multicore CPUs. With taskset you can set its CPU affinity to run on only one core.

    taskset -c 0 your_command
    Alanceil · 2009-02-28 22:38:02 1
  • If shell escaping of the command is problematic, you can write the command to a file first: batch <somefile Or read it: read -re && echo "$REPLY" | batch Or, if your shell supports it, you can eliminate echo: read -re && batch <<<$REPLY ("man batch" lists 1.5 for me, but I don't know how widely it differs.)

    echo 'some command' | batch
    kniht · 2010-07-14 03:08:31 0
  • For each cpu set mask and then monitor your cpu infos. Temp,load avg. etc. For example for 2nd cpu or 2nd core taskset 0x00000002 yes > /dev/null & For example for 3rd cpu or 3rd core taskset 0x00000004 yes > /dev/null & For example for 4th cpu or 4th core taskset 0x00000008 yes > /dev/null & Monitor your cpu temp with this command if you want watch -n1 "acpi -t" Load avg. from top command top

    taskset 0x00000001 yes > /dev/null &
    kerim · 2011-04-03 07:23:53 0

  • 7
    sudo lshw -C cpu|grep width
    sliceoflinux · 2009-09-24 11:43:00 0
  • [ 2000 -ge "$(free -m | awk '/buffers.cache:/ {print $4}')" ] returns true if less than 2000 MB of RAM are available, so adjust this number to your needs. [ $(echo "$(uptime | awk '{print $10}' | sed -e 's/,$//' -e 's/,/./') >= $(grep -c ^processor /proc/cpuinfo)" | bc) -eq 1 ] returns true if the current machine load is at least equal to the number of CPUs. If either of the tests returns true we wait 10 seconds and check again. If both tests return false, i.e. 2GB are available and machine load falls below number of CPUs, we start our command and save it's output in a text file. The ( ( ... ) & ) construct lets the command run in background even if we log out. See .

    ( ( while [ 2000 -ge "$(free -m | awk '/buffers.cache:/ {print $4}')" ] || [ $(echo "$(uptime | awk '{print $10}' | sed -e 's/,$//' -e 's/,/./') >= $(grep -c ^processor /proc/cpuinfo)" | bc) -eq 1 ]; do sleep 10; done; my-command > output.txt ) & )
    michelsberg · 2010-07-13 09:12:11 0

  • 4
    ps -ef --sort=-%cpu
    aguslr · 2011-10-14 21:57:51 0
  • Similar to `cpulimit`, although `prlimit` can be found shipped with recent util-linux. Example: limit CPU consumption to 10% for a math problem which ordinarily takes up 100% CPU: Before: bc -l <(echo "1234123412341234^12341234") See the difference `prlimit` makes: prlimit --cpu=10 bc -l <(echo "1234123412341234^12341234") To actually monitor the CPU usage, use `top`, `sar`, etc.. or: pidstat -C 'bc' -hur -p ALL 1

    prlimit --cpu=10 sort -u hugefile
    mhs · 2013-02-27 15:59:11 3

  • 3
    slow2() { ionice -c3 renice -n 20 $(pstree `pidof $1` -p -a -u -A|gawk 'BEGIN{FS=","}{print $2}'|cut -f1 -d " ") ; }
    oernii3 · 2010-11-18 10:50:17 0
  • There is no need for variables. I also added sleep to reduce cpu usage, however I didn't test it.

    while :; do acpi -t | osd_cat -p bottom ; sleep 1; done &
    John_W · 2011-01-14 13:57:45 4
  • I've wanted this for a long time, finally just sat down and came up with it. This shows you the sorted output of ps in a pretty format perfect for cron or startup scripts. You can sort by changing the k -vsz to k -pmem for example to sort by memory instead. If you want a function, here's one from my aa_top_ps(){ local T N=${1:-10};T=${2:-vsz}; ps wwo pid,user,group,vsize:8,size:8,sz:6,rss:6,pmem:7,pcpu:7,time:7,wchan,sched=,stat,flags,comm,args k -${T} -A|sed -u "/^ *PID/d;${N}q"; } Show Sample Output

    command ps wwo pid,user,group,vsize:8,size:8,sz:6,rss:6,pmem:7,pcpu:7,time:7,wchan,sched=,stat,flags,comm,args k -vsz -A|sed -u '/^ *PID/d;10q'
    AskApache · 2010-05-18 18:41:38 1
  • Once you know the available frequencies for your CPU, they can be used to do things like set minimum CPU frequency for powerd so that it doesn't ramp down too slow on a server : /etc/sysctl.conf or /boot/loader.conf: debug.cpufreq.lowest=DESIRED FREQ HERE or at terminal sysctl debug.cpufreq.lowest=DESIRED FREQ HERE Show Sample Output

    sysctl dev.cpu.0.freq_levels
    bugmenot · 2010-09-18 11:19:46 0
  • No need for a colon, and one less semicolon too. Also untested.

    while sleep 1; do acpi -t | osd_cat -p bottom; done &
    linuts · 2011-01-14 23:22:57 0
  • Watch the temperatures of your CPU cores in real time at the command line. Press CONTROL+C to end. GORY DETAILS: Your computer needs to support sensors (many laptops, for example, do not). You'll need to install the lm-sensors package if it isn't already installed. And it helps to run the `sensors-detect` command to set up your sensor kernel modules first. At the very end of the sensors-detect interactive shell prompt, answer YES to add the new lines to the list of kernel modules loaded at boot. Show Sample Output

    while :; do sensors|grep ^Core|while read x; do printf '% .23s\n' "$x"; done; sleep 1 && clear; done;
    linuxrawkstar · 2011-04-20 06:41:57 2
  • This version is precise and requires one second to collect statistics. Check sample output for a more generic version and also a remote computer invocation variant. It doesn't work with the busybox version of the 'top' command but can be adjusted Show Sample Output

    top -bn2|awk -F, '/Cpu/{if (NR>4){print 100-gensub(/.([^ ]+).*/,"\\1","g",$4)}}'
    ichbins · 2014-04-18 17:48:05 0
  • # 4 cores with 2500 pi digits CPUBENCH 4 2500 . every core will use 100% cpu and you can see how fast they calculate it. if you do 50000 digitits and more it can take hours or days Show Sample Output

    CPUBENCH() { local CPU="${1:-1}"; local SCALE="${2:-5000}"; { for LOOP in `seq 1 $CPU`; do { time echo "scale=${SCALE}; 4*a(1)" | bc -l -q | grep -v ^"[0-9]" & } ; done }; echo "Cores: $CPU"; echo "Digit: $SCALE" ;}
    emphazer · 2018-05-14 17:30:37 0
  • Using the output of 'ps' to determine CPU usage is misleading, as the CPU column in 'ps' shows CPU usage per process over the entire lifetime of the process. In order to get *current* CPU usage (without scraping a top screen) you need to pull some numbers from /proc/stat. Here, we take two readings, once second apart, determine how much IDLE time was spent across all CPUs, divide by the number of CPUs, and then subtract from 100 to get non-idle time. Show Sample Output

    NUMCPUS=`grep ^proc /proc/cpuinfo | wc -l`; FIRST=`cat /proc/stat | awk '/^cpu / {print $5}'`; sleep 1; SECOND=`cat /proc/stat | awk '/^cpu / {print $5}'`; USED=`echo 2 k 100 $SECOND $FIRST - $NUMCPUS / - p | dc`; echo ${USED}% CPU Usage
    toxick · 2012-10-02 03:57:51 1

  • -1
    ps aux | awk {'sum+=$3;print sum'} | tail -n 1
    tailot · 2011-07-16 16:16:59 0
  • Broken in two parts, first get the number of cores with cat /proc/cpuinfo |grep proc|wc -l and create a integer sequence with that number (xargs seq), then have GNU parallel loop that many times over the given command. Cheers! Show Sample Output

    time cat /proc/cpuinfo |grep proc|wc -l|xargs seq|parallel -N 0 echo "scale=4000\; a\(1\)\*4" '|' bc -l
    kostis · 2018-12-06 05:15:24 2

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