Java peformance taking a dip going from RHEL 5 -> RHEL 6 ?

[Steve]

Hi. I'm at an org working on an SWT application compiled in Java 1.6 and we use Eclipse 3.8. We could have Eclipse up and the app up, having evertying run at OK speeds on a 32 bit version of RHEL 5.1. We upgraded to RHEL 6.5, 64 bit, keeping the same hardware. Now the speeds are making our setups almost unusable.

Anyone else have this experience?

Any ideas what could be causing it?

Any ideas for a cure aside more RAM?

Thanks.

[Roedy Green]

Now the speeds are making our se=
tups almost unusable.

RHEL = Red Hat Enterprise Linux

You have the same Java compiler and the same run time, right?

You could just sit tight and wait for Oracle to re-optimise the run
time.
You could try using Jet for Linux. See
http://mindprod.com/jgloss/jet.html

Have a look over all buffer sizes. Perhaps the new Linux is not as
clever.

See http://mindprod.com/jgloss/profiler.html to find out where it is
eating up the time.

[Steve]

On Tue, 25 Feb 2014 06:30:44 -0800 (PST), Steve
You have the same Java compiler and the same run time, right?

Yep, the IBM version, which I understand is better for Linux. Same hardware too.

You could try using Jet for Linux. See
http://mindprod.com/jgloss/jet.html

Did not know about that, thanks.

Have a look over all buffer sizes. Perhaps the new Linux is not as
clever.

Thanks. We have a big networking department who I am sure is eventually going to be called to task. I am just curious as to what the problem could be. That is an education comment, thanks.

[Nigel Wade]

Post by Steve
Hi. I'm at an org working on an SWT application compiled in Java 1.6 and we use Eclipse 3.8. We could have Eclipse
up and the app up, having evertying run at OK speeds on a 32 bit version of RHEL 5.1. We upgraded to RHEL 6.5, 64
bit, keeping the same hardware. Now the speeds are making our setups almost unusable.

Firstly, SWT is not part of Java. So it may not be Java that's your problem.

Have you ascertained exactly where in your code the delay is being caused? Is it in CPU performance, disk I/O or
graphics (SWT library)?

Post by Steve
Anyone else have this experience?

No.

Post by Steve
Any ideas what could be causing it?

Something not optimized correctly for the hardware. I'd look at whether the SWT and/or your graphics driver are
optimized for your hardware. Does SWT use OpenGL, have you setup the correct X driver, and OpenGL configuration?

Post by Steve
Any ideas for a cure aside more RAM?

I can't think why more RAM would help.