竹炉山房

Original article

By Steven J. Vaughan-Nichols | July 17, 2011, 1:45pm PDT

Cats and dogs; apples and oranges; Linux and Microsoft. Two of these three things do not go together. Would you believe that Microsoft—yes Microsoft—was the fifth largest contributor to the soon to be released Linux 3.0 kernel? Believe it.

In a Linux Weekly News story, currently only available to subscribers, an analysis of Linux 3.0 contributors reveals that Microsoft was the fifth largest corporate contributer to Linux 3.0. While only 15h overall, that still puts Microsoft behind only Red Hat, Intel, Novell, and IBM in contributing new code to this version of Linux.

To be exact, Microsoft developer K. Y Srinivasan gets the credit for helping to improve Linux. Of course, as you might guess, neither Srinivasan nor Microsoft are doing this due to any particular love tor Linux per se.

The vast bulk of Microsoft’s contributions has been to its own Hyper-V virtualization hypervisor drivers. Hyper-V is Microsoft’s 64-bit hypervisor-based virtualization system. It’s Microsoft’s answer to VMware and Linux’s own native Kernel-based Virtualization Manager (KVM).

Microsoft you see wants it to be possible for both Linux to run Server 2008 R2 instances and for Windows 2008 R2 to run Linux instances using its own virtualizaton tools. Microsoft has been working on this for some time with Novell, now SUSE.

At first, this code wasn’t open-sourced at all, but in 2009, it was discovered that some GPL code was already in Hyper-V’s Linux drivers. So it was that “In a break from the ordinary, Microsoft released 20,000 lines of device driver code to the Linux community. The code, which includes three Linux device drivers, has been submitted to the Linux kernel community for inclusion in the Linux tree. The drivers will be available to the Linux community and customers alike, and will enhance the performance of the Linux operating system when virtualized on Windows Server 2008 Hyper-V or Windows Server 2008 R2 Hyper-V.”

It also helped, of course, that Microsoft, ever so reluctantly, has been forced to work with Linux to try to keep their market share. As Matt Asay, a noted open-source executive and author said at the time, “The news reflects Microsoft’s continued interest in lobotomizing its virtualization competition through low prices, but also the recognition that it must open up if it wants to fend off insurgent virtualization strategies from Red Hat, Novell, and others in the open-source camp.”

In the months after that though Microsoft did little to improve its code. Indeed Greg Kroah-Hartman, who oversees code staging to the Linux kernel, has complained at times that “The [Microsoft] developers again seem to have disappeared, this is getting old” and he threatened to remove the code from Linux.

Microsoft seems to have finally gotten the message. In the last few months they’ve worked hard to improve Hyper-V and Linux interoperability.

This may not last, and it’s really only for Microsoft’s own goals, but for now, Microsoft, yes Microsoft, is a leading contributor to Linux. Now, in these days of miracles, let me see if I can get my dogs to stop barking at my neighbors’ cats.