Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Multiple CPU - How to read linux Load Average?
New on LowEndTalk? Please Register and read our Community Rules.

Multiple CPU - How to read linux Load Average?

dnwkdnwk Member

I thought in Linux/Ubuntu the load average has something related to how many CPUs do you have? Is it right? If one CPU/Core that anything above 1 in load means you are overloaded. And I also read that if you have more than 1 CPU the number should be read differently?
My question: how to read the load average, if you have more than 1 CPU/

Designers: www.linkun.info

Comments

  • If you have 4 CPU's for example and a CPU load of 25% that means 1 of the 4 cores is being 100% utilized. A CPU load of 50% would mean 2 of your 4 cores are being 100% utilized and so on.

  • @Fliso
    I think Linux Load average is like 0.5 1.2 2.3 not a percentage

    Designers: www.linkun.info

  • MiniVZMiniVZ Member
    edited December 2013

    If 1 out of 4 CPUs are running at 100% each, Load will be 1.0

    If 4 out of 4 CPUs are running at 50% each, Load will be 2.0

    If 4 out of 4 CPUs are running at 100% each, Load will be 4.0

    Thanked by 1mawr
  • So, I have 4 CPUs and if the load average is 1.2, there is nothing to worry about, right?

    Designers: www.linkun.info

  • @dnwk said:
    So, I have 4 CPUs and if the load average is 1.2, there is nothing to worry about, right?

    That depends on what is causing the load. The load itself is not a real good indicator if something is to worry about. You will see that regular jobs (see crontab) might for a few seconds cause a high load. But they are intended to be done, so it's fine.

  • edited December 2013

    @MiniVZ said:
    If 1 out of 4 CPUs are running at 100% each, Load will be 1.0

    If 4 out of 4 CPUs are running at 50% each, Load will be 2.0

    If 4 out of 4 CPUs are running at 100% each, Load will be 4.0

    Nope, 1.0 means there is 1 running process (mean 1, 5 ,15min)

  • mahjongmahjong Member
    edited December 2013

    Hi all!

    My question is: if i have a vps where i can only utilize one cpu with a load average of 0.9 (and i can only use one cpu), then:

    how comes if i set cpulimit to 80% that load average (uptime) is way above 0.8. I just cant understand it. I/O is minimal, no other services running that are using cpu... so how comes that if i can only use one cpu (I am phisically limited to it), and i limit it to 80% that load average is above 1?

    Thanks for all answer!

    Edit:

    Found the answer: i was not limited to one core physically, so cpulimit was not working. After setting the number of threads in my application (the number of used cores) cpulimit works very well.

  • i have a kimsufi and my load is always around 1.2 to 1.4 and im not even stressing that bitch( just multiple websites).The good thing is i dont have to worry about being warned for utilizing the cpu lol.

    vpsdash.com - Tips and tricks in life, information and technology news to get things done

  • smansman Member
    edited December 2013

    Load of 1 is equivalent to 100% and you multiply it by # of physical cores. Ignore hyperthreaded cores.

    That is just one # to consider because it depends a lot what you are doing and how that load is distributed.

    If it is mostly due to CPU load and your application is sensitive to I/O then an average load of 4 on a 4 core might not be too bad. If most of that load is I/O that could really slow things. Again, depends on what you are doing.

    Some people run at much higher than 4 on a 4 core with no problems. For others it could cause complaints. I know someone whos single core server runs at an average load of 20, CPU pinned and memory all used up so I/O swapping like crazy. However it's not a problem for them because it's an email server.

  • @sman said:
    Some people run at much higher than 4 on a 4 core with no problems. For others it could cause complaints. I know someone who's single core server runs at an average load of 20, CPU pinned and memory all used up so I/O swapping like crazy. However it's not a problem for them because it's an email server.

    >

    Load 20 ? You will heard from your provider....

    Designers: www.linkun.info

  • @dnwk said:

    It's not a provider. It's a private server in a private rack.

  • @sman said:
    It's not a provider. It's a private server in a private rack.

    I am running a mail server too. But I don't want system load goes that high. It will means my Web Mail is extremely slow.

    Designers: www.linkun.info

  • @cosmicgate said:
    i have a kimsufi and my load is always around 1.2 to 1.4 and im not even stressing that bitch( just multiple websites).The good thing is i dont have to worry about being warned for utilizing the cpu lol.

    Try caching your websites, it'll reduce your cpu / load. For instance my wordpress sites were using 15-25% per page load on my intel atom. With quickcache I think it now uses a maximum of 3% per page load.

  • @cosmicgate said:
    i have a kimsufi and my load is always around 1.2 to 1.4 and im not even stressing that bitch( just multiple websites).The good thing is i dont have to worry about being warned for utilizing the cpu lol.

    Also if you cache, the pages will load faster :)

Sign In or Register to comment.