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#1 (**permalink**) 01-05-2008, 09:32 AM

Hi Guys

When i joined my new company tw weeks ago , i found one of the Lpar was
working with 100% CPU utilization .... I , after two weeks added
another processor into that Lpar using DLPAR and found that now CPU
utilization was reduced to exactly 50%.

Now , when i did more research on the issue , i found that actually
still only one processor is 100% in use while the other processor is
literally doing nothing but free all the time.

So question is that why the other processor is not being utilized ...
is the application is not a multithread application / not a DLPAR aware
application or this is default behavior of AIX .

Can , by any means , i force the OS to utilize both processors ... any
ideas /suggestions ???

Regards

Huyed Jones

#2 (**permalink**) 01-05-2008, 09:32 AM

If there is a constant 100% (or 50% in case of two processors) it test
if
there is a process being gone 'mad'. Have you search which process is
using the capacity?
And to answer your other questions, yes AIX uses more than one
processor :-)

Bye, Stefan ... . . . .

#3 (**permalink**) 01-05-2008, 09:32 AM

Jones wrote:
> Hi Guys
> So question is that why the other processor is not being utilized ...
> is the application is not a multithread application / not a DLPAR aware
> application or this is default behavior of AIX .

The high usage is likely to be a single thread in a loop (I am
speculating based in my own personal experience). The AIX "truss -p PID"
command can be used to verify if the process is looping (if it is
continuously making the same system call/s)

Perhaps "man bindprocessor" may be useful to you as well.

Regards,
Niel

#4 (**permalink**) 01-05-2008, 09:33 AM

Just to clarify, the gest of the other two replies is that cpu
utilization should not be 100%. Usually it is way down and goes up and
down over time.

#5 (**permalink**) 01-05-2008, 09:36 AM

Hi Guys

I am experiencing same problem all the time . The one processor is
90-100% utilized , when system is on load conditions ( like after noon
) while other remain 0-10%
utilized.

Over all system shows 50% processor utilization , which is quite
obviuos .

However , my perception is that being mutiprocessor system , both of
processors should be equally utilized .I can see that one of the
process ( KSorder ) is utilizing CPU=50% continuosly ( as shown by
topas ) ... How can i cause this process to utilize both processors
...... Can binprocessor command cause this process and its all threads
to be bind to both processes... Please advice !!!

Regards

Huyed Jones

#6 (**permalink**) 01-05-2008, 09:37 AM

Jones wrote:
> Hi Guys
>
> I am experiencing same problem all the time . The one processor is
> 90-100% utilized , when system is on load conditions ( like after noon
> ) while other remain 0-10%
> utilized.
>
> Over all system shows 50% processor utilization , which is quite
> obviuos .
>
> However , my perception is that being mutiprocessor system , both of
> processors should be equally utilized .I can see that one of the
> process ( KSorder ) is utilizing CPU=50% continuosly ( as shown by
> topas ) ... How can i cause this process to utilize both processors
> ..... Can binprocessor command cause this process and its all threads
> to be bind to both processes... Please advice !!!
>
> Regards
>
> Huyed Jones
>

The _program_ has to be able to make use of multiple processors. It is
the concept of single threaded versus multi-threaded programming. If
the program is single threaded, only one processor will be utilized even
if there are 32 available.

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Only one processor is in use... what AIX Does ????