Entries tagged with operating systems - Channel 9

Windows Embedded: Past, Present and Future

Charles — Thu, 12 Nov 2009 21:14:00 GMT

Windows Embedded Standard is a general purpose OS, based on the Windows codebase, that is highly modular and fine tuned to run on a number of devices ranging in size and complexity (but less powerful and kess general purpose in nature than your average PC) that are x86/x64 powered (casino gaming consoles, retail kiosks, hand-held devices, etc). The next version of Windows Embedded Standard will arrive some time in 2010 - thus the name Windows Embedded Standard 2011.

Windows Embedded is the general term for all Windows embedded products including Windows Embedded Standard, Windows Embedded Compact (aka CE), Windows Embedded Server, Windows Embedded Enterprise.

For the Windows Embedded Standard product line, product examples are Windows XP Embedded (aka XPe), Windows Embedded Standard 2009, Windows Embedded Standard 2011, Windows Embedded POSReady 2009.

We figured it would be a good idea to meet some of the developers who write Windows Embedded Standard to get a better understanding of, well, exactly what it is and where it is going. Here, we meet and chat with Windows Embedded Standard developers Oren Winter, Jon Parati, Mike Moini and Milong Sabandith. What are the key new features in Windows Embedded Standard 2011? What is Windows Embedded Standard 2011, exactly? What's Windows Embedded CE, again? How is Windows Embedded related to Windows proper? Windows Embedded Standard 2011 is built from the same sources that make up Windows 7? What's different between the two and why? How is Windows Embedded Standard able to be so modular? What's the developer story for Windows Embedded Standard 2011? And more. Tune in. Classic Channel 9.

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C9 Conversations: Yousef Khalidi on Cloud Computing

Charles — Wed, 11 Nov 2009 00:46:00 GMT

Yousef Khalidi is a Distinguished Engineer with a rich history in both operating system design and distributed computing. Yousef is responsible for the overall design of Windows Azure, Microsoft's cloud operating system (which includes the Azure development platform in addition to the "OS", aka Windows Azure). Windows Azure is an operating system in the sense that it supplies a host of core services, process scheduling and management, identity management, etc, that we typically expect from a general purpose operating system.

In this first installment of C9 Conversations (we sit down with various Microsoft technical leaders to discuss a wide range of topics related to general purpose computing; all in high quality video and audio (big thanks to Tina Summerford for producing this new series)), the topic is cloud computing. What is it, exactly? Why does it matter? What are the challenges involved in taking software to the cloud? What does that mean, exactly? Is Windows Azure an operating system by analogy? What is Windows Azure, exactly? And more..

Yousef will be presenting his ideas on cloud computing and its future at PDC09 as part of the Technical Leaders track. Make sure to attend his talk if you're interested in how Microsoft thinks about the future of cloud computing.

Silviu Calinoiu: Inside Windows 7 - Fault Tolerant Heap

Charles — Tue, 25 Aug 2009 05:35:00 GMT

The Fault Tolerant Heap (FTH) is a subsystem of Windows 7 responsible for monitoring application crashes and autonomously applying mitigations to prevent future crashes on a per application basis. For the vast majority of users, FTH will function with no need for intervention or change on their part.

Principal Development Lead and rock star developer Silviu Calinoiu is the mastermind behind FTH. Here, we go deep into how FTH works and why it's designed the way it is.

The Fault Tolerant Heap is another example of the low level efficiency built into the system: FTH automatically corrects memory faults that cause applications to crash which has the pleasant side effect of preventing future crashes. How does FTH work, exactly? What types of memory problems does it address, specifically? How do developers monitor FTH events and can they override FTH's behavior? What does this all mean to the average user?

FTH, as an autonomous monitoring and correction system, represents a step in the right direction for the evolution of a more homeostatic general purpose operating system. Simply, Windows is getting smarter in the sense that it's increasingly becoming better at self-regulation and self-healing. Yes, there's a very long way to go, but we're making real progress.

You will continue to learn about recoverability in Windows over the coming months here on C9.

Tune in.

Arun Kishan: Inside Windows 7 - Farewell to the Windows Kernel Dispatcher Lock

Charles — Thu, 06 Aug 2009 17:28:00 GMT

You've learned about many of the new features of the latest version of the Windows kernel in the Mark Russinovich Inside Windows 7 conversation here on Channel 9. One of Mark’s favorite kernel innovations is the way the Windows 7 kernel manages scheduling of threads and the underlying synchronization primitives that embody kernel thread management.

Prior to Windows 7 (and therefore Windows Server 2008 R2) the Windows kernel dispatcher employed a single lock, the dispatcher lock, which worked well for a relatively small numbers of processors (like 64). However, now that we find ourselves in the midst of the ManyCore era, well, 64 processors aren’t that many... A new strategy was required to scale Windows to large numbers of processors since a single lock is limited in capability, by design: The masterful David Cutler, one of the world's greatest software engineers, wrote the NT scheduler in a time when the notion of affordable 256-processor machines was more science fiction than probable.

As we learned in the Mark Russinovich video, Windows 7 can now scale to 256 processors thanks to the great engineering of Arun Kishan, a kernel architect you've met on C9 back in the Vista days. In order to promote further scalability of the NT kernel, Arun completely eliminated the dispatcher lock and replaced it with a much finer grained set of synchronization primitives. Gone are the days of contention for a single spinlock. How did Arun pull this off, exactly, you ask? Who is this genius? Well, tune in. Lots of answers await…

Arun's work directly benefits the overall performance of Windows running on many processors and means, simply, Windows can now really scale. Thank you, Arun!

Spinlocks are synchronization primitives that cause a processor to busy-wait until the state of the lock’s memory location changes.

As the name implies, the dispatcher lock is the fundamental lock associated with the kernel dispatcher, or the scheduler.

Expert to Expert: Helen Wang and Alex Moshchuk - Inside Gazelle

Charles — Tue, 07 Apr 2009 17:48:00 GMT

Microsoft Research was in the news not too long ago regarding the innovative, outside-the-box research being done by MSR scientists on display at the annual MSR TechFest event. One of the stars of the show was a new web browser project named Gazelle.

Gazelle is a Microsoft Research prototype web browser constructed as a multi-principal OS (emphasis on research and prototype). From the Gazelle Microsoft Research Technical Report: Gazelle’s Browser Kernel is an operating system that exclusively manages resource protection and sharing across web site principals. This construction exposes intricate design issues that no previous work has identified, such as legacy protection of cross-origin script source, and cross-principal, cross-process display and events protection.

Interesting, Captain. This really piqued our curiosity so Erik Meijer and I decided to find out the inside scoop on Gazelle. Why choose an OS architecture to model a web browser? How does it work, exactly? What does multi-principal mean in the context of execution of web pages? Aren't we talking about isolated processes? What happens when a principal is compromised? Is the browser kernel completely isolated from code executing in a principal context(is it possible to "blue screen" Gazelle)? What are the intrinsic challenges with implementing this design? How performant is a multi-principal, kernel-based web browser (what if you have 40 principal contexts running simultaneously, for example)?

This is a great conversation with Gazelle project lead Helen Wang and Alex Moshchuk, a PhD student intern developer working on the Gazelle project. We cover a lot of ground and Erik and I are unusually curious given the fascinating model Gazelle represents for a truly secure web browser.

Enjoy! This is a birthday present from Channel 9 to you!

Dave Probert: Inside Windows 7 - User Mode Scheduler (UMS)

Charles — Mon, 02 Feb 2009 20:11:00 GMT

Here, we continue our exploration of the morphology of Windows 7 on Going Deep with windows kernel architect Dave Probert. You may remember him from an early four part episode of Going Deep where he teaches us about general purpose operating system architectures and history: Part 1, Part 2, Part 3, Part 4

That was a great conversation from a few years ago and it's been way too long since we returned to Windows kernel world to converse with and learn from Dr. Probert. Not surprisingly, Dave has been busy innovating the Windows core.

Dave and team, working very closely with the Parallel Computing Platform People, have created a very compelling new user mode thread scheduling/management system in Windows 7. In a nutshell, the User Mode Scheduler provides a new model for high-performance applications to control the execution of threads by allowing applications to schedule, throttle and control the overhead due to blocking system calls. In other words, applications can switch user threads completely in user mode without going through the kernel level scheduler. This frees up the kernel thread scheduler from having to block unnecessarily, which is a very good thing as we move into the age of Many-Core... Speaking of Many-Core, remember the piece we did on the Concurrency Runtime (ConcRT)? ConcRT is built on top of UMS and is the best way to most effectively utilize this new user mode thread scheduling model in Windows 7.

Make yourself comfortable and spend some time watching and listening to Dave make all of this crystal clear.

This is another great conversation with a fantastic OS architect and Windows kernel professor. Lots to learn here. Enjoy.

Chittur Subbaraman: Inside Windows 7 - Service Controller and Background Processing

Charles — Fri, 23 Jan 2009 19:39:00 GMT

At any given point, Windows is executing a lot of code. Some of this code runs in the background as services. In pre Windows 7 operating systems some services were set to auto run even though the configuration of the system (installed apps, hardware, etc) did not warrant them running. This had a four-fold potential effect:

1) Windows might start up slower as the service fires up
2) Users may experience sluggish performance as the service runs taking up processing and memory resources
3) Windows might take a long time to shut down as the service shuts down, unwinding itself and cleaning up it's resources
4) The surface area for code-level security breaches is larger(though, since Vista, most services run in a restricted security context)

Chittur Subbaraman, Windows kernel developer extraordinaire, and team spent a great deal of time thinking about and rectifying these problems by re-architecting the Windows 7 Service Controller. They also identified services that don't need to auto run (like a TabletPC Pen service that need not ever run on a desktop (non-Tablet) machine by default). But they went much further than simply figuring out which services can be set to manual start-up state in Windows 7. They added a new feature for service developers based on the trigger pattern: services can be started and shut down via triggers - this means developers are able to specify programmatically when a service needs to start or stop. This allows Wndows to control services in a much more dynamic way so less code has to run in any given user session. The Service Controller monitors and reacts to trigger events as opposed to just running services marked as auto when the system starts. Less code running in the background on Windows means more resources available for foregrond processing, faster start up of sessions and faster shut down.

The great work in the Windows 7 service controller by Chittur and team has a direct impact on the performance of Windows 7. Tune in to learn about the details and history of the service controller (and Task Manager).

Here are some great resources for you to read to get the details behind all of this great engineering in the background processing mechanisms deep inside Windows 7.

·White paper on Designing Efficient Background Processes.

·PDC talk on Designing Efficient Background Processes.

Mark Russinovich: Inside Windows 7

Charles — Wed, 14 Jan 2009 19:39:00 GMT

How has Windows evolved, as a general purpose operating system and at the lowest levels, in Windows 7? Who better to talk to than Technical Fellow and Windows Kernel guru Mark Russinovich? Here, Mark enlightens us on the new kernel constructs in Windows 7 (and, yeah, we do wander up into user mode, but only briefly). One very important change in the Windows 7 kernel is the dismantling of the dispatcher spin lock and redesign and implementation of its functionality. This great work was done by Arun Kishan (you've met him here on C9 last year). EDIT: You can learn exactly what Arun did in eliminating the dispatcher lock and replacing it with a set of synchronization primitives and a new "pre-wait" thread state, here. The direct result of the reworking of the dispatcher lock is that Windows 7 can scale to 256 processors. Further, this enabled the great Landy Wang to tune the Windows Memory Manager to be even more efficient than it already is. Mark also explains (again) what MinWin really is (heck, even I was confused. Not anymore...). MinWin is present in Windows 7. Native support for VHD (boot from VHD anyone?) is another very cool addition to our next general purpose OS. Yes, and there's more!

Tune in. This is a great conversation (if you're into operating systems). It's always great to chat with Mark.

Richard Ward: Windows Architecture - Past, Present and Future

Charles — Fri, 07 Nov 2008 17:30:00 GMT

Artists embody a diverse set of talents and interests. This gives them a rich array of experiences to draw upon in their work. In the same way, Richard Ward brings an eclectic background and collection of interests to his efforts at Microsoft. He brings this diversity to his own art of programming within the Windows Core Architecture team.

While most Windows developers are focusing on the next version of Windows, Richard and his team are already hard at work on the version which will follow. In this episode of Behind The Code, we will discover what experiences Richard finds most helpful, as he focuses on building out the core infrastructure components of what will, one day, be running on the vast majority of the world’s computers.

Read Richard Ward’s { End Bracket } column in MSDN Magazine.