Monday, May 5, 2008

PowerVM Lx86. Technology that works.

PowerVM Lx86. Running Linux 32-bit x86 apps on Power systems. Slick. Super-easy with Linux. And does it work? Absolutely.

Now, as a performance analyst, I'm often asked: "Is it a performance play?" My quick answer: "Nah - not usually..."   But for everything I've tried: "It just works" - which in and of itself is pretty cool. You really want the best performance for your app? Re-compile and run it natively. Duh. You want easy access to existing x86 compiled apps? Give this product a shot. And in some cases, the performance of the translated product is just fine for the user's needs.

In essence, this product is the flip-side of Transitive's translator technology for Apple which translates older Apple Power applications to run on the new x86-based Apple systems. Check out these web sites if you missed the technology introduction several years ago:


IBM and Transitive (http://transitive.com/customers/ibm) have already introduced the second release (Ver 1.2) of the IBM PowerVM Lx86 product.

Originally discussed in the press as p-AVE (for example, see an article from http://www.it-analysis.com/), IBM's product naming wizards must have been at work with the preliminary name of IBM System p Application Virtual Environment (System p AVE). Later they followed it with a newer official name under the IBM PowerVM umbrella as PowerVM Lx86 for x86 Linux applications. "p-AVE" certainly rolled off the tongue far easier than the PowerVM Lx86 name. But the PowerVM naming admit'ably fits better with the overall virtualization strengths of the Power line.

For a page full of pointers and interesting helpful hints, check out http://www-128.ibm.com/developerworks/linux/lx86/.

  • For example, the product is download'able from IBM's web site... gotta dig through the DeveloperWorks various registration pages - but you're looking for: IBM PowerVM Lx86 V1.2 (formerly System p Application Virtual environment or p AVE) p-ave-1.2.0.0-1.tar (8,294,400 bytes).

For a clever approach to using PowerVM Lx86, a nice demo was created which you can see on YouTube.

  • I really like this demo since it highlights one of several cases where the translation performance of the product isn't perceivable to an end user. The demo is an actual run, no tricks. As the demo narrative says, when you try to execute an x86 application on the Power system, the x86 executable is automatically recognized and the translation environment invoked.

  • The video clip goes on to show some of the highlights of the Power line where Power logical partitions can be migrated from one physical system to another. More cool stuff.


Another example of common product usage is in the world of graphing performance results. Users can check out a really nice set of charting libraries from Advanced Software Engineering (http://www.advsofteng.com/) available with the ChartDirector product. The executable run-time libraries are available for a variety of platforms, including Linux on i386, but alas, not for Linux on ppc64 systems. But when the i386 libraries are installed on a Power system running Linux with the additional PowerVM Lx86 product, Power users can use the graphing routines directly. Again, the perceptible performance differences are minimal, and the full function of the i386 routines are available to the Power users.

The IBM web site for PowerVM Virtualization Software offerings has a good description of the capabilities of the Linux product and the services available for software vendors to enable their apps for native execution while still exploiting the Power systems running Linux with their existing applications.

Keep in mind there are the normal obligatory footnotes and qualifications on what i386 applications can function under this product - check out the product web sites for that information.

Finally, as a performance team, we always tend to agonize over the corner cases which highlight the performance challenges of translating an application from one system platform base to another, and there certainly are some areas where performance can be a challenge. Java is a good example. There are too many steps of translating byte codes to executables, then those executables are translated again to execute on the Power platform, which can make for a rather poor execution path. If your Java app is a minor piece of a bigger application (the prime example is as an application installer), shrug. But whew, if you're thinking about snagging a full comprehensive Java based product and running it in in translation mode - as opposed to verifying that the Java code runs on the Power platform - I can anticipate you may be disappointed with the performance. One would've hoped that the Java world of write once, run anywhere would've panned out better than the write once test everywhere implementation.

In the meantime, if you need easy access to x86 executables and applications on your Power systems, give this a shot.

2 comments:

Anonymous said...

Is there any support for SSE instructions?

Bill Buros said...

Alas no.

As I understand it, the environment presents itself as an older platform which doesn't support SSE, and in our experience most x86 apps test for this before they try to use it.

One of many bloggers.

Bill Buros

Bill leads an IBM Linux performance team in Austin Tx (the only place really to live in Texas). The team is focused on IBM's Power offerings (old, new, and future) working with IBM's Linux Technology Center (the LTC). While the focus is primarily on Power systems, the team also analyzes and improves overall Linux performance for IBM's xSeries products (both Intel and AMD) , driving performance improvements which are both common for Linux and occasionally unique to the hardware offerings.

Performance analysis techniques, tools, and approaches are nicely common across Linux. Having worked for years in performance, there are still daily reminders of how much there is to learn in this space, so in many ways this blog is simply another vehicle in the continuing journey to becoming a more experienced "performance professional". One of several journeys in life.

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