The man page of ps says following for the C column:
Quote:
C
(-f, l, and -l flags) CPU utilization of process or thread, incremented each time the system clock ticks and the
process or thread is found to be running. The value is decayed by the scheduler by dividing it by 2 once per
second. For the sched_other policy, CPU utilization is used in determining process scheduling priority. Large
values indicate a CPU intensive process and result in lower process priority whereas small values indicate an I/O
intensive process and result in a more favorable priority.
I guess that value can just vary on different boxes with different applications running on them. It sounds for me as if this is just to be taken in relationship in it's own respect.
I just checked it on one of our busy boxes and all processes are 0 in that case. So maybe it is not the best way to judge if a process uses a lot of CPU time - you simply have to see if there is any difference when your defunct process shows up.
Maybe use something like:
.. and look for the %CPU column and the STAT column (ie. what nmon and topas show for process activity too).
If this doesn't help for your question and you don't get another more insightful answer how this value of the C column takes effect in calculating cpu times, maybe open up a parallel thread in the IBM Developer's community.
Hi,
I have a process that can be seen after "ps aux" command.
However when I do "top" command. This process
cannot be seen.
How can this happen? Is there anything wrong
with my code? (3 Replies)
Hi Friends,
Can any of you explain me about the below line of code?
mn_code=`env|grep "..mn"|awk -F"=" '{print $2}'`
Im not able to understand, what exactly it is doing :confused:
Any help would be useful for me.
Lokesha (4 Replies)
Hi guys,
I am still kinda new to Linux.
Script template I found on the net and adapted for our environment:
#!/bin/sh
#set -x
ADMIN="admin@mydomain.com"
ALERT=10
df -H | grep -vE '^Filesystem|tmpfs|cdrom' | awk '{ print $5 " " $1 }' | while read output;
do
#echo $output
... (2 Replies)
Hi,
I have line in input file as below:
3G_CENTRAL;INDONESIA_(M)_TELKOMSEL;SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL
My expected output for line in the file must be :
"1-Radon1-cMOC_deg"|"LDIndex"|"3G_CENTRAL|INDONESIA_(M)_TELKOMSEL"|LAST|"SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL"
Can someone... (7 Replies)
The system don't boot.
on the screen appears following:
press enter to maintenance (or type CTRL-D to continue)...I checked with format command.
... the slices "0-root","1-swap","2-backup" exist.
...the slises "3-var","6-usr" -unassigned. :( (16 Replies)
How to use "mailx" command to do e-mail reading the input file containing email address, where column 1 has name and column 2 containing “To” e-mail address
and column 3 contains “cc” e-mail address to include with same email.
Sample input file, email.txt
Below is an sample code where... (2 Replies)
Hello.
System : opensuse leap 42.3
I have a bash script that build a text file.
I would like the last command doing :
print_cmd -o page-left=43 -o page-right=22 -o page-top=28 -o page-bottom=43 -o font=LatinModernMono12:regular:9 some_file.txt
where :
print_cmd ::= some printing... (1 Reply)
Hi 2 all,
i have had AIX 7.2
:/# /usr/IBMAHS/bin/apachectl -v
Server version: Apache/2.4.12 (Unix)
Server built: May 25 2015 04:58:27
:/#:/# /usr/IBMAHS/bin/apachectl -M
Loaded Modules:
core_module (static)
so_module (static)
http_module (static)
mpm_worker_module (static)
... (3 Replies)
Discussion started by: penchev
3 Replies
LEARN ABOUT POSIX
ionice
IONICE(1) User Commands IONICE(1)NAME
ionice - set or get process I/O scheduling class and priority
SYNOPSIS
ionice [-c class] [-n level] [-t] -p PID...
ionice [-c class] [-n level] [-t] -P PGID...
ionice [-c class] [-n level] [-t] -u UID...
ionice [-c class] [-n level] [-t] command [argument...]
DESCRIPTION
This program sets or gets the I/O scheduling class and priority for a program. If no arguments or just -p is given, ionice will query the
current I/O scheduling class and priority for that process.
When command is given, ionice will run this command with the given arguments. If no class is specified, then command will be executed with
the "best-effort" scheduling class. The default priority level is 4.
As of this writing, a process can be in one of three scheduling classes:
Idle A program running with idle I/O priority will only get disk time when no other program has asked for disk I/O for a defined grace
period. The impact of an idle I/O process on normal system activity should be zero. This scheduling class does not take a priority
argument. Presently, this scheduling class is permitted for an ordinary user (since kernel 2.6.25).
Best-effort
This is the effective scheduling class for any process that has not asked for a specific I/O priority. This class takes a priority
argument from 0-7, with a lower number being higher priority. Programs running at the same best-effort priority are served in a
round-robin fashion.
Note that before kernel 2.6.26 a process that has not asked for an I/O priority formally uses "none" as scheduling class, but the
I/O scheduler will treat such processes as if it were in the best-effort class. The priority within the best-effort class will be
dynamically derived from the CPU nice level of the process: io_priority = (cpu_nice + 20) / 5.
For kernels after 2.6.26 with the CFQ I/O scheduler, a process that has not asked for an I/O priority inherits its CPU scheduling
class. The I/O priority is derived from the CPU nice level of the process (same as before kernel 2.6.26).
Realtime
The RT scheduling class is given first access to the disk, regardless of what else is going on in the system. Thus the RT class
needs to be used with some care, as it can starve other processes. As with the best-effort class, 8 priority levels are defined
denoting how big a time slice a given process will receive on each scheduling window. This scheduling class is not permitted for an
ordinary (i.e., non-root) user.
OPTIONS -c, --class class
Specify the name or number of the scheduling class to use; 0 for none, 1 for realtime, 2 for best-effort, 3 for idle.
-n, --classdata level
Specify the scheduling class data. This only has an effect if the class accepts an argument. For realtime and best-effort, 0-7 are
valid data (priority levels), and 0 represents the highest priority level.
-p, --pid PID...
Specify the process IDs of running processes for which to get or set the scheduling parameters.
-P, --pgid PGID...
Specify the process group IDs of running processes for which to get or set the scheduling parameters.
-t, --ignore
Ignore failure to set the requested priority. If command was specified, run it even in case it was not possible to set the desired
scheduling priority, which can happen due to insufficient privileges or an old kernel version.
-h, --help
Display help text and exit.
-u, --uid UID...
Specify the user IDs of running processes for which to get or set the scheduling parameters.
-V, --version
Display version information and exit.
EXAMPLES
# ionice -c 3 -p 89
Sets process with PID 89 as an idle I/O process.
# ionice -c 2 -n 0 bash
Runs 'bash' as a best-effort program with highest priority.
# ionice -p 89 91
Prints the class and priority of the processes with PID 89 and 91.
NOTES
Linux supports I/O scheduling priorities and classes since 2.6.13 with the CFQ I/O scheduler.
AUTHORS
Jens Axboe <jens@axboe.dk>
Karel Zak <kzak@redhat.com>
SEE ALSO ioprio_set(2)AVAILABILITY
The ionice command is part of the util-linux package and is available from https://www.kernel.org/pub/linux/utils/util-linux/.
util-linux July 2011 IONICE(1)