"Load average" in top is actually the run queue average length.
Over 1 means on average things are waiting on the cpu, below 1 means on average no-one has to wait. Don't confuse this with %cpu - it's not like that.
The bold summary line show percentages should always be across all the cores, but can get confused if you have the wrong version of top, so always add them up to check you get 100 the first time you use top on a new machine to check this.
As for process %cpu, that depends on your version of top - if it's compiled for your arcihtecture properly, it understands and the % is how much of one CPU is beign used (so more than 100% would require multithreading across multiple cores).
To complicate matters further, a system running at 100% cpu might not be terrible if your shceduler is beign smart - it could well be that you've got a bunch of low priority things in the background that get a bunch of work done while the system is idel, then throtle back when you need it - ie sitting at 100% you might still find that your CPU hungry command you want to run goes just fine and the cpu load happily stays at 100% during and after. It's often a waste of time to monitor CPU percentages overall.
Better is to look at:
* overall wait % ("wa") - you don't want that to get very high or it indicates something is thrashing in swap or disk.
* run queue length
In your java example:
Its saying that you have a Priority 23 task, (lower numbers get priority on CPU time) using 70.6% of your free memory and 142.9% of one CPU (ie it's multithreaded and is using about 1.5 Cores).
Last edited by Smiling Dragon; 08-08-2013 at 11:34 PM..
Reason: added the java example breakdown.
This User Gave Thanks to Smiling Dragon For This Post:
we have an unix system which has
load average normally about 20.
but while i am running a particular unix batch which performs heavy
operations on filesystem and database average load
reduces to 15.
how can we explain this situation?
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Hi,
I'm new to shell scripting. I need to make a script to add on to my cronjobs.
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Hi,
i have installed solaris 10 on t-5120 sparc enterprise.
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Hi Folks,
We have 6 processors in our sun server. I do see that CPU usage by one of the processor is always more than 70-80% and for remaining 5 processors, its only 20%. Is there a way to delegate the excess CPU load on one of the processors in server to other processors in same server? Is... (3 Replies)
Hello AlL,..
I want from experts to help me as my load average is increased and i dont know where is the problem !!
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how load average is calculated and what exactly is it
difference between cpu% and load average (9 Replies)
Discussion started by: robo
9 Replies
LEARN ABOUT DEBIAN
uptime
UPTIME(1) User Commands UPTIME(1)NAME
uptime - Tell how long the system has been running.
SYNOPSIS
uptime [options]
DESCRIPTION
uptime gives a one line display of the following information. The current time, how long the system has been running, how many users are
currently logged on, and the system load averages for the past 1, 5, and 15 minutes.
This is the same information contained in the header line displayed by w(1).
System load averages is the average number of processes that are either in a runnable or uninterruptable state. A process in a runnable
state is either using the CPU or waiting to use the CPU. A process in uninterruptable state is waiting for some I/O access, eg waiting for
disk. The averages are taken over the three time intervals. Load averages are not normalized for the number of CPUs in a system, so a
load average of 1 means a single CPU system is loaded all the time while on a 4 CPU system it means it was idle 75% of the time.
OPTIONS -h, --help
display this help text
-V, --version
display version information and exit
FILES
/var/run/utmp
information about who is currently logged on
/proc process information
AUTHORS
uptime was written by Larry Greenfield <greenfie@gauss.rutgers.edu> and Michael K. Johnson <johnsonm@sunsite.unc.edu>
SEE ALSO ps(1), top(1), utmp(5), w(1)REPORTING BUGS
Please send bug reports to <procps@freelists.org>
procps-ng June 2011 UPTIME(1)