{"id":13814,"date":"2019-04-06T09:36:15","date_gmt":"2019-04-06T09:36:15","guid":{"rendered":"http:\/\/www.appservgrid.com\/paw92\/?p=13814"},"modified":"2019-04-06T09:36:15","modified_gmt":"2019-04-06T09:36:15","slug":"limit-cpu-usage-of-a-process-in-linux-with-cpulimit-tool","status":"publish","type":"post","link":"https:\/\/www.appservgrid.com\/paw92\/index.php\/2019\/04\/06\/limit-cpu-usage-of-a-process-in-linux-with-cpulimit-tool\/","title":{"rendered":"Limit CPU Usage of a Process in Linux with CPULimit Tool"},"content":{"rendered":"

In an earlier post, we\u2019ve explained\u00a0CPUTool for limiting and controlling CPU utilization<\/a>\u00a0of any process in Linux. It allows a system administrator to interrupt execution of a process (or process group) if the CPU\/system load goes beyond a defined threshold. Here, we will learn how to use a similar tool called\u00a0cpulimit<\/strong>.<\/p>\n

Cpulimit<\/strong>\u00a0is used to restrict the CPU usage of a process in the same way as\u00a0CPUTool<\/strong>, however, it offers more usage options compared to its counterpart. One important difference is that cpulimit doesn\u2019t manage system load unlike\u00a0cputool<\/strong>.<\/p>\n

Suggested Read:<\/b>\u00a09 Useful Commands to Get CPU Information on Linux<\/a><\/p>\n

Install CPULimit to Limit CPU Usage Of a Process in Linux<\/h3>\n

CPULimit<\/strong>\u00a0is available to install from default software repositories of\u00a0Debian\/Ubuntu<\/strong>\u00a0and its derivatives using a package management tool.<\/p>\n

$ sudo apt install cpulimit\r\n<\/pre>\n
In\u00a0RHEL\/CentOS<\/strong>\u00a0and\u00a0Fedora<\/strong>, you need to first enable\u00a0EPEL repository<\/a>\u00a0and then install cpulimit as shown.<\/p>\n
# yum install epel-release
\n# yum install cpulimit<\/p>\n
Limiting Process CPU Usage With CUPLimit<\/h4>\n
In this sub section, we\u2019ll explain how cpulimit works. First, let\u2019s run a command (same\u00a0dd command<\/strong>\u00a0we looked at while covering cputool) which should result into a high CPU percentage, in the background (note that the process PID is printed out after running the command).<\/p>\n
$ dd if=\/dev\/zero of=\/dev\/null &\r\n\r\n[1] 17918\r\n<\/pre>\n
Next, we can use the\u00a0top<\/a>\u00a0or\u00a0glances<\/a>\u00a0tools which output the actual frequently updated state of a running Linux system, to watch the CPU usage of the command above.<\/p>\n
$ top\r\n<\/pre>\n
\n
\"Monitor<\/p>\n
Monitor CPU Usage in Linux<\/p>\n<\/div>\n
Looking at the output above, we can see that the\u00a0dd<\/strong>\u00a0process is utilizing the highest percentage of CPU time\u00a0100.0%<\/strong>.<\/p>\n
But we can limit this using cputlimit as follows. The\u00a0--pid<\/code>\u00a0or\u00a0-p<\/code>\u00a0option is used to specify the PID and\u00a0--limit<\/code>\u00a0or\u00a0-l<\/code>\u00a0is used to set a usage percentage for a process.<\/p>\n
The command below will limit the\u00a0dd command<\/strong>\u00a0(PID 17918<\/strong>) to\u00a050%<\/strong>\u00a0use of one CPU core.<\/p>\n
$ sudo cpulimit --pid 17918 --limit 50  \r\n\r\nProcess 17918 detected\r\n<\/pre>\n
Once we run cpulimit, we can view the current CPU usage for the\u00a0dd command<\/strong>\u00a0with\u00a0top<\/a>\u00a0or\u00a0glances<\/a>. From the output, the value ranges from (51.5%-55.0%<\/strong>\u00a0or slightly beyond).<\/p>\n
\n
\"Limit<\/p>\n
Limit CPU Usage of Process in Linux<\/p>\n<\/div>\n
We can throttle its CPU usage for a second time as follows, this time lowering the percentage further as follows:<\/p>\n
$ sudo cpulimit --pid 17918 --limit 20 \r\n\r\nProcess 17918 detected\r\n<\/pre>\n
As we did before, we can run top or glances to view the new CPU usage for the process, which will range from\u00a020%-25.0%<\/strong>\u00a0or slightly beyond this.<\/p>\n
$ top\r\n<\/pre>\n
\n
\"Throttle<\/p>\n
Throttle CPU Usage in Linux<\/p>\n<\/div>\n
Note<\/strong>: The shell becomes un-interactive \u2013 doesn\u2019t expect any user input when cpulimit is running. To kill it (which should stop the CPU usage limitation operation), press\u00a0[Ctrl + C]<\/code>.<\/p>\n
To run cpulimit as a background process, use the\u00a0--background<\/code>\u00a0or\u00a0-b<\/code>\u00a0switch, freeing up the terminal.<\/p>\n
$ sudo cpulimit --pid 17918 --limit 20 --background\r\n<\/pre>\n
To specify the number of CPU cores present on the system, use the\u00a0--cpu<\/code>\u00a0or\u00a0-c<\/code>\u00a0flag (this is normally detected automatically).<\/p>\n
$ sudo cpulimit --pid 17918 --limit 20 --cpu 4\r\n<\/pre>\n
Rather than limit a process\u2019s CPU usage, we can kill it with the\u00a0--kill<\/code>\u00a0or\u00a0-k<\/code>\u00a0option. The default is signal sent to the process is\u00a0SIGCONT<\/strong>, but to send a different signal, use the\u00a0--signal<\/code>\u00a0or\u00a0-s<\/code>\u00a0flag.<\/p>\n
$ sudo cpulimit --pid 17918 --limit 20 --kill \r\n<\/pre>\n
To exit if there is no suitable target process, or in case it dies, include the\u00a0-z<\/code>\u00a0or\u00a0--lazy<\/code>\u00a0like this.<\/p>\n
$ sudo cpulimit --pid 17918 --limit 20 --kill --lazy\r\n<\/pre>\n
For additional information and usage options, view the cpulimit man page.<\/p>\n
$ man cpulimit\r\n<\/pre>\n
Do check out the following useful guides for finding CPU info and CPU\/system performance monitoring.<\/p>\n
    \n
  1. Find Top Running Processes by Highest Memory and CPU Usage in Linux<\/a><\/li>\n
  2. Cpustat \u2013 Monitors CPU Utilization by Running Processes in Linux<\/a><\/li>\n
  3. CoreFreq \u2013 A Powerful CPU Monitoring Tool for Linux Systems<\/a><\/li>\n
  4. Find Top Running Processes by Highest Memory and CPU Usage in Linux<\/a><\/li>\n
  5. 20 Command Line Tools to Monitor Linux Performance<\/a><\/li>\n
  6. 13 Linux Performance Monitoring Tools \u2013 Part 2<\/a><\/li>\n<\/ol>\n
    In comparison, after testing\u00a0CPUTool<\/a>\u00a0and\u00a0CPULimit<\/strong>, we noticed that the former offers a more effective and reliable \u201cprocess CPU usage limitation\u201d functionality.<\/p>\n
    This is according to the percentage range of CPU usage observed after running both tools against a given process. Try out both tools and add your thoughts to this article using the feedback form below.<\/p>\n
    Source<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
    In an earlier post, we\u2019ve explained\u00a0CPUTool for limiting and controlling CPU utilization\u00a0of any process in Linux. It allows a system administrator to interrupt execution of a process (or process group) if the CPU\/system load goes beyond a defined threshold. Here, we will learn how to use a similar tool called\u00a0cpulimit. Cpulimit\u00a0is used to restrict the … <\/p>\n
    Continue reading “Limit CPU Usage of a Process in Linux with CPULimit Tool”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-13814","post","type-post","status-publish","format-standard","hentry","category-linux"],"_links":{"self":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts\/13814","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/comments?post=13814"}],"version-history":[{"count":1,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts\/13814\/revisions"}],"predecessor-version":[{"id":13815,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts\/13814\/revisions\/13815"}],"wp:attachment":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/media?parent=13814"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/categories?post=13814"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/tags?post=13814"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}