bind CPUs to the process?

[Rosaline Fan]

Hello,
We are using AIX5L V5.2.
I'd like to know if AIX support binding multiple CPUs to one process
(single process, multiple threads)?
Does anyone use this way for your production system?
Is there any new features in V5 talking about CPU bound applications?
If we use 32-bit process, how much the space can be used by the user's
data? (my testing show it is only 2G. Am I missing something?)
BTW, the process I mentioned here is the application server which is
written in JAVA. There is no I/O concern during the whole processing.

Thanks in advance,
Rosaline

[Nicholas Dronen]

Rosaline Fan <fanruox@sbcglobal.net> wrote:
RF> Hello,
RF> We are using AIX5L V5.2.
RF> I'd like to know if AIX support binding multiple CPUs to one process
RF> (single process, multiple threads)?

Yes:

[url]http://www.google.com/search?&q=aix+bindprocessor[/url]

RF> Does anyone use this way for your production system?

Some people use Workload Manager (WLM) for resource control.
It's part of AIX 5.x, IIRC:

[url]http://www.google.com/search?&q=WLM+AIX[/url]

RF> Is there any new features in V5 talking about CPU bound applications?

Not sure what you mean.

RF> If we use 32-bit process, how much the space can be used by the user's
RF> data? (my testing show it is only 2G. Am I missing something?)

Two GB is the maximum positive value of a 32-bit signed integer,
or so my shoddy math tells me:

$ perl -wle 'print int eval (((0xffffffff>>1)/1024)/1024);'
2047

But I forget about all of AIX's use-this-flag-to-access- memory-segment-42
bells and whistles. Wait for Gary Hook to pipe up. (Gary's famous.
He even has a 1-900 hotline for obscure AIX questions. :-)

RF> BTW, the process I mentioned here is the application server which is
RF> written in JAVA. There is no I/O concern during the whole processing.

Java? You'll definitely need the memory. :-)

--
"Why shouldn't I top-post?" [url]http://www.aglami.com/tpfaq.html[/url]
"Meanings are another story." [url]http://www.ifas.org/wa/glossolalia.html[/url]

[Ken Wallis]

Rosaline Fan wrote:

> We are using AIX5L V5.2.
> I'd like to know if AIX support binding multiple CPUs to one process
> (single process, multiple threads)?
> Does anyone use this way for your production system?
> Is there any new features in V5 talking about CPU bound applications?
> If we use 32-bit process, how much the space can be used by the user's
> data? (my testing show it is only 2G. Am I missing something?)
> BTW, the process I mentioned here is the application server which is
> written in JAVA. There is no I/O concern during the whole processing.

try 'man bindprocessor'

Cheers,

Ken

[Gary R. Hook]

Nicholas Dronen wrote:

> Rosaline Fan <fanruox@sbcglobal.net> wrote:
> RF> Hello,
> RF> We are using AIX5L V5.2.
> RF> I'd like to know if AIX support binding multiple CPUs to one process
> RF> (single process, multiple threads)?
>
> [url]http://www.google.com/search?&q=aix+bindprocessor[/url]

Although it's unclear why you would want to do that. WLM
would be more suitable for constraining CPU use, and if all you
want is to run a thread on any CPU, the system will handle that
for you.

> RF> If we use 32-bit process, how much the space can be used by the user's
> RF> data? (my testing show it is only 2G. Am I missing something?)
>
>
> But I forget about all of AIX's use-this-flag-to-access- memory-segment-42
> bells and whistles.

You can make a program a large data program using
LDR_CNTRL=MAXDATA=0xD0000000/DSA
which allows up to 3.25 GB of heap space for the process. You
lose access to the shared lib segments, tho, and modules will
get stuck into segment 2 at exec, the heap for dynamic loads.

If you're talking about Java, you probably don't want to do
this. I don't think the JVM supports DSA (dynamic segment
allocation). If you need more space, use the 64-bit version
of Java (on 64-bit hardware).

--
Gary R. Hook / AIX PartnerWorld for Developers / These opinions are MINE
__________________________________________________ ______________________

[Rosaline Fan]

"Gary R. Hook" wrote:

> Nicholas Dronen wrote:
>

> > Rosaline Fan <fanruox@sbcglobal.net> wrote:
> > RF> Hello,
> > RF> We are using AIX5L V5.2.
> > RF> I'd like to know if AIX support binding multiple CPUs to one process
> > RF> (single process, multiple threads)?
> >
> > [url]http://www.google.com/search?&q=aix+bindprocessor[/url]

>
> Although it's unclear why you would want to do that. WLM
> would be more suitable for constraining CPU use, and if all you
> want is to run a thread on any CPU, the system will handle that
> for you.

Thanks Gary and Nicholas. That is very helpful.
My fault, I have been supporting db server so long time. Sometimes it is not a
good thing. DB2 agent is single process, single thread, so there is no way for
one db2agent use multiple processors. But the application server I am talking
here is single process/multiple threads,... so I don't need BINDING any more.

>
>

> > RF> If we use 32-bit process, how much the space can be used by the user's
> > RF> data? (my testing show it is only 2G. Am I missing something?)
> >
> >
> > But I forget about all of AIX's use-this-flag-to-access- memory-segment-42
> > bells and whistles.

>
> You can make a program a large data program using
> LDR_CNTRL=MAXDATA=0xD0000000/DSA
> which allows up to 3.25 GB of heap space for the process. You
> lose access to the shared lib segments, tho, and modules will
> get stuck into segment 2 at exec, the heap for dynamic loads.

I did some testing today. For the 32bit C/C++ application, it can only be
allowed to use 256M heap size. If you require a heap size more than 256M, I have
to use LARGE MEMORY MODEL, or compile to 64bit application.

>
>
> If you're talking about Java, you probably don't want to do
> this. I don't think the JVM supports DSA (dynamic segment
> allocation).

Me either.
For the 32bit JVM(1.4.x), I can set a bigger maximum heap size
(1000000000bytes). (Maybe that is the reason why I can only attach 4 connections
to db server shared memory).
Even from the OS viewpoint both C/C++ application and Java application are the
user processes. Even they use similar approach to increase the heap size (By
sacrificing segments available for shared memory segments). Even JVM on AIX is
also developed by IBM. But when setup/configure JVM maximum heap size, it has to
follow the way on the other platforms which developed by SUN.
Regards,
Rosaline Fan

> If you need more space, use the 64-bit version
> of Java (on 64-bit hardware).
>
> --
> Gary R. Hook / AIX PartnerWorld for Developers / These opinions are MINE
> __________________________________________________ ______________________

[Rosaline Fan]

Thank you, Ken.
Rosaline Fan

Ken Wallis wrote:

> Rosaline Fan wrote:
>

> > We are using AIX5L V5.2.
> > I'd like to know if AIX support binding multiple CPUs to one process
> > (single process, multiple threads)?
> > Does anyone use this way for your production system?
> > Is there any new features in V5 talking about CPU bound applications?
> > If we use 32-bit process, how much the space can be used by the user's
> > data? (my testing show it is only 2G. Am I missing something?)
> > BTW, the process I mentioned here is the application server which is
> > written in JAVA. There is no I/O concern during the whole processing.

>
> try 'man bindprocessor'
>
> Cheers,
>
> Ken