The load average is a statistic invented at BSD and the concept has migrated from there to most versions of unix pretty much intact. Linux was a complete reimplementation and I too find conflicting information in various Linux articles on the Internet. So I read the kernel source code to get a straight answer. The statistic is calculated in the module called timer.c This excerpt is relevant:
So a task is counted if it is in the states:
TASK_UNINTERRUPTIBLE
TASK_RUNNING
TASK_UNINTERRUPTIBLE is the exact equivalent of sleeping with a priority lower than PZERO and this does indeed include all "fast I/O". TASK_RUNNING does not mean it currently has a CPU, rather it like the Unix run queue. So even in Linux, the "load" is a count of processes that need CPU now or very soon.
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?
while running that batch idle cpu time is about %60-65... (0 Replies)
Hello all, I have a question about load averages.
I've read the man pages for the uptime and w command for two or three different flavors of Unix (Red Hat, Tru64, Solaris). All of them agree that in the output of the 2 aforementioned commands, you are given the load average for the box, but... (3 Replies)
Hi,
i have installed solaris 10 on t-5120 sparc enterprise.
I am little surprised to see load average of 2 or around on this OS.
when checked with ps command following process is using highest CPU. looks like it is running for long time and does not want to stop, but I do not know... (5 Replies)
Hello AlL,..
I want from experts to help me as my load average is increased and i dont know where is the problem !!
this is my top result :
root@a4s # top
top - 11:30:38 up 40 min, 1 user, load average: 3.06, 2.49, 4.66
Mem: 8168788k total, 2889596k used, 5279192k free, 47792k... (3 Replies)
Hi,
Does anyone seem this kind of output from uptime and top where "load average: inf, inf, inf"
is this possible problem with the processor?
Cpu states:
CPU LOAD USER NICE SYS IDLE BLOCK SWAIT INTR SSYS
0 0.10 5.4% 0.0% 4.0% 90.6% 0.0% 0.0% 0.0% 0.0%... (1 Reply)
Hi ,
I am using 48 CPU sunOS server at my work.
The application has facility to check the current load average before starting a new process to control the load.
Right now it is configured as 48. So it does mean that each CPU can take maximum one proces and no processe is waiting.
... (2 Replies)
Hi,
On load average graph, unit is 100m, 200m, 300...800m.
I don't understand what it means.
Thx for helping (3 Replies)
Discussion started by: Michenux
3 Replies
LEARN ABOUT CENTOS
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 -p, --pretty
show uptime in pretty format
-h, --help
display this help text
-s, --since
system up since, in yyyy-mm-dd MM:HH:SS format
-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 December 2012 UPTIME(1)