Microsoft contributes a lot of changes to Linux kernel 3.0
The 343 changes made by Microsoft developer K. Y. Srinivasan put him at the top of a list, created by LWN.net, of developers who made the most changes in the current development cycle for Linux 3.0. Along with a number of other "change sets", Microsoft provided a total of 361 changes, putting it in seventh place on the list of companies and groups that contributed code to the Linux kernel. By comparison, independent developers provided 1,085 change sets to Linux 3.0, while Red Hat provided 1,000 and Intel 839.
The figures were published on Thursday in an LWN.net article which is available exclusively to subscribers until this coming Thursday (21 July); however, bloggers have already commented on the figures. LWN.net has produced similar analyses for all of the recently published kernels, including 2.6.39 and 2.6.38. Author, kernel developer, and LWN.net founder Jonathan Corbet has conducted such surveys in cooperation with the Linux Foundation and published them as studies. In that context, The H pointed out that you have to be careful in interpreting the numbers. One bone of contention is that the analysis also covers changes in the staging area, which contains code that does not fulfil the quality standards of its developers and of kernel developers; a large number of changes are made to produce these required improvements.
Staging code is also concerned here, as Srinivasan improved the driver for Microsoft's HyperV virtualisation interface published two years ago. Not much progress has been made since, and staging maintainer Greg Kroah-Hartman has even twice threatened to remove the drivers from the kernel's staging area. A few months ago, however, the work done by Microsoft developers increased considerably when they began taking care of the well-known quality issues so that the driver can leave the staging area someday; staging maintainer Kroah-Hartman even praised the company recently for the work it did on the development of Linux kernel 3.0, which will probably be released in the next few days.
In the aforementioned list, Srinivasan comes in at the top because he made a lot of minor changes. And that's exactly what kernel developers want; a change that only affects a single line counts as much as a giant change that is a megabyte in size. In LWN.net's evaluation of the number of lines of code changed, Srinivasan and Microsoft are therefore nearer the bottom of the list. LWN.net found that Microsoft developers changed 11,564 lines of code (1.3 per cent) – compared to Intel's 163,232 (18.1 per cent). The figure given for Intel has also come under criticism because the new isci driver in 3.0 that led to the high number was taken up too early and had to be considerably revised in subsequent commits (eg 1). This approach was chosen to retain the change history, but it obviously also led to a better ranking at LWN.net.