Sponsored Content
Homework and Emergencies Emergency UNIX and Linux Support How to fix the CPU bound issues on AIX? Post 302860369 by bakunin on Saturday 5th of October 2013 06:30:12 PM
Old 10-05-2013
OK, this clearly looks CPU-bound:

First, have a look at the "us", "sy", "id" and "wa" columns of the "cpu" part: these are percentages, denoting the time the processors spent (on average) in the "users", "system", "idle" and "wait" parts of processing: "user" is roughly your programs, "system" is kernel activity and other system services, "idle" is when no process is running and "wait" is like idle, but with I/O operations outstanding. If you would have high "wait" percentages it would hint to a I/O-bound system, but this isn't the case here. In fact your system is busy to saturation running your application, which is as it should be. If it is too slow the only thing that helps is more processing power.

Alas the system cannot get more processors right now. The last column, "ec" is the "entitled capacity" and it is at near 100(%) too. LPARs get some share of the systems processors per default, but can be entitled to some bigger amount should the necessity arise. These additional resources are dynamically added should the system get near saturation and are dynamically relinquished once the situation gets less demanding. This system already has already allocated as much as it will ever get and this still isn't enough.

Now, lets look at the top line of the output: you have 10 logical CPUs. What a "logical CPU" comprises (some fraction of a physical CPU) depends on the physical CPU backing it and ultimately on the hard you run: POWER5? POWER6? POWER7? It might be that 10 lCPUs are a poor layout for your underlying hardware and overtax the physical CPUs with too many context switches.

Anyway, you definitely have to add CPUs to this LPAR: at the HMC modify the LPAR profile to add more (physical) CPUs as "desired" and also increase the "maximum" processors to a new sensible value. To know what a "sensible value" for "maximum" is you probably will have to monitor the system for a while, so go with a good estimation and change that after a few days. After you changed the profile you will have to reboot (cold reboot/power cycle - simple "shutdown -r" won't help) to have the new profile used.

I hope this helps.

bakunin
These 2 Users Gave Thanks to bakunin For This Post:
 

9 More Discussions You Might Find Interesting

1. AIX

AIX 5.3 Issues

We are planning to move to AIX 5.3 and we would like to know if someone has had any 'bad' experiences with it. We have a 32PE p690 Regatta and currently we are running the latest AIX 5.2 with the latest patches. Has anyone any interesting points to mention when transitioning to AXI 5.3? Is... (1 Reply)
Discussion started by: miket
1 Replies

2. AIX

If the AIX need reboot after install fix pack or APAR?

After install fix pack or APAR, if aix need reboot? if not, do we need stop database and all applications before we install fix pack or APAR? (3 Replies)
Discussion started by: rainbow_bean
3 Replies

3. AIX

IY17981 fix required for aix 4.3.3 to aix 5L migration but not found

Hi, redbook documentation is telling that IY17981 fix is required for aix 4.3.3 to aix 5L migration. But there is no mention about that fix in any ML installation packages. - My system is ML11 : oslevel –r 4330-11 - But xlC.rte is on wrong version : lslpp -L xlC.rte xlC.rte ... (3 Replies)
Discussion started by: astjen
3 Replies

4. AIX

AIX filter Issues

Hi, I want to print from AIX 5.3/6.1 using 'pr' preprocessing filter and 'PCL' print file type. Steps: 1. Smitty 2. Print Spooling 3. Create a print queue(remote->Generic) 4. change the attributes for that print queue. 5. Change print file type to PCL and... (1 Reply)
Discussion started by: meeraramanathan
1 Replies

5. AIX

How to install AIX Fix Pack 5300-06-06-0811

Hi All, I have this fix for AIX (5300-06-06-0811) and i need to install it. How can i do this? What are the prerequisites for this fix? Thanks (1 Reply)
Discussion started by: lucaxvu
1 Replies

6. AIX

APAR fix on AIX 53tl9

We have tried to install an APAR fix IZ20298 on a AIX test server. It is requiring a base level of bos.adt.prof of 5.3.0.0 I cannot find this file anywhere. I fould 5.3.0.1 and it still will not install without the base install. Any ideas where I can find bos.adt.prof 5.3.0.0? (1 Reply)
Discussion started by: daveisme
1 Replies

7. AIX

AIX CPU use

Hi Could somebody explain me how AIX is using CPU?? For example when we have 2 processors system is giving all task to one of them till 100% is used ?? Or it's depend on configuration or anything else ?? Best regards enda (3 Replies)
Discussion started by: enda
3 Replies

8. AIX

AIX Fix Pack update

Hi All, i'm try to update my aix 6100.06.05 to 6100.07.00. i download the 4,5 GB of FixPack buy i don't have a required package (devices.chrp.pci.rte 6.1.7.0) This package does not exist on the fix pack (i've check in the .toc file and in the .bff files) On ibm website i see that this... (0 Replies)
Discussion started by: Zio Bill
0 Replies

9. AIX

AIX CPU waits

Guys, I have a question - when nmon reports a sizeable %CPU wait, does that mean - 1) IO operations are slowing CPU down, OR 2) paging slowing the CPU down, OR 3) one cant tell?? I thought the nmon documentation clearly suggested that CPU waits reported in nmon were from disk... (4 Replies)
Discussion started by: getback0
4 Replies
hostinfo(8)						    BSD System Manager's Manual 					       hostinfo(8)

NAME
hostinfo -- host information SYNOPSIS
hostinfo DESCRIPTION
The hostinfo command displays information about the host system on which the command is executing. The output includes a kernel version description, processor configuration data, available physical memory, and various scheduling statistics. OPTIONS
There are no options. DISPLAY
Mach kernel version: The version string compiled into the kernel executing on the host system. Processor Configuration: The maximum possible processors for which the kernel is configured, followed by the number of physical and logical processors avail- able. Note: on Intel architectures, physical processors are referred to as cores, and logical processors are referred to as hardware threads; there may be multiple logical processors per core and multiple cores per processor package. This command does not report the number of processor packages. Processor type: The host's processor type and subtype. Processor active: A list of active processors on the host system. Active processors are members of a processor set and are ready to dispatch threads. On a single processor system, the active processor, is processor 0. Primary memory available: The amount of physical memory that is configured for use on the host system. Default processor set: Displays the number of tasks currently assigned to the host processor set, the number of threads currently assigned to the host proces- sor set, and the number of processors included in the host processor set. Load average: Measures the average number of threads in the run queue. Mach factor: A variant of the load average which measures the processing resources available to a new thread. Mach factor is based on the number of CPUs divided by (1 + the number of runnablethreads) or the number of CPUs minus the number of runnable threads when the number of runnable threads is less than the number of CPUs. The closer the Mach factor value is to zero, the higher the load. On an idle system with a fixed number of active processors, the mach factor will be equal to the number of CPUs. SEE ALSO
sysctl(8) Mac OS X October 30, 2003 Mac OS X
All times are GMT -4. The time now is 06:32 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy