JVM performance tuning

Embedded devices are virtually everywhere

By Jason Tee

TheServerSide.com

If you’ve been paying any attention to the enterprise landscape lately, you know that virtualization technology is hot. Virtualized servers and hypervisors are what make cloud computing possible, and cloud computing is changing the way IT professionals design their systems. But you might be challenged to think about how virtualization is also changing the embedded device market. Virtualization is everywhere, from data grids to smartphones and tablets, helping to improve the performance of embedded security kernels and concurrent operating systems.

It was actually mainframe developers who pioneered the ideas and concepts behind virtualization technology, but it wasn’t until these concepts were ported to the server side that enthusiasm spiked and levels of acceptance skyrocketed. As every systems architect knows, enterprise server utilization is not particularly efficient under extremely high loads, which causes problems when dealing with peak capacities.

Through virtualization, however, many server instances run on a single server, which lets hardware, support and real estate costs to be both shared and reduced. From server side virtualization, we saw desktop virtualization take off with the introduction of type-2 hypervisors. Now the end  user workstation could run concurrent operating systems with servers very efficiently supporting a network of “thin” virtualized clients.

But this third wave is happening today, as virtualization is spreading into the embedded device market; However, virtualized embedded devices are not leveraging the same old hypervisors you might find floating around in your servers and desktops. The hypervisors that run on embedded devices and make virtualization possible on the tiniest of microprocessors has some unique and special attributes that set it apart from its server side and desktop brethren, including:

Efficiency and Performance
In addition to processor sharing, which is a common concern for all hypervisors striving for efficiency, limited memory is also a primary restriction on embedded device performance and efficiency that is not seen in traditional virtualization environments. To meet that challenge, an embedded hypervisor must be very small and very memory efficient. Virtualization makes that possible.

Strong Security
In most operating systems, the hypervisor runs in privileged mode and is the only system component to do so. This gives the smaller virtualized hypervisor an advantage as its smaller code base can be more quickly validated as being bug-free. A number of vendors will even guarantee the security and integrity of their embedded hypervisors. In privileged mode, the hypervisor serves as a “trusted computing base” and provides a more secure, high-performance platform.

Interactive Communications
Although privileged, embedded hypervisors also improve communications with non-privileged applications. Since they are built for the purpose of sharing hardware platforms with multiple users and other applications, manufacturers often expand their functionality to facilitate communications and interaction between those elements as well.  

Isolation
As virtualized embedded devices have become more open in their interfaces and licensing, manufacturers want those devices to co-exist with commercial software, proprietary applications, and open source software. There are communication mechanisms enabled by virtualization that help isolate apps and users from each other. This isolation improves security and license segregation. Each function can now coexist with the others in isolated environments.  

Real-time scheduling
The embedded virtualized hypervisor must also coexist with apps operating on a best-effort basis. For example, smartphones make use of embedded devices to share the computing platform in real-time with the unit’s communication technology and any third-party apps that have been downloaded.  Real-time scheduling capability enables those critical functions to work together.

  
The use of virtualization on embedded devices will only grow as applications require more and more security and performance from smaller and smaller hardware platforms. Given their size, powerful capabilities, reasonable cost and core security features, virtualized hypervisors are ready to revolutionize the way we use, develop and interact with embedded devices of all types.

15 Jun 2011

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