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Code Quality In Open and Closed Source Kernels

Diomidis Spinellis writes "Earlier today I presented at the 30th International Conference on Software Engineering a research paper comparing the code quality of Linux, Windows (its research kernel distribution), OpenSolaris, and FreeBSD. For the comparison I parsed multiple configurations of these systems (more than ten million lines) and stored the results in four databases, where I could run SQL queries on them. This amounted to 8GB of data, 160 million records. (I've made the databases and the SQL queries available online.) The areas I examined were file organization, code structure, code style, preprocessing, and data organization. To my surprise there was no clear winner or loser, but there were interesting differences in specific areas. As the summary concludes: '..the structure and internal quality attributes of a working, non-trivial software artifact will represent first and foremost the engineering requirements of its construction, with the influence of process being marginal, if any.'"

8 of 252 comments (clear)

  1. Re:Is it just me? by Anonymous Coward · · Score: 5, Insightful

    That is if you can figure out which of the 12 links are the actual FA and which are supporting material.

  2. No-one has ever claimed by wellingtonsteve · · Score: 4, Insightful

    ..that Open Source code is of quality, but at least the point of things like the GPL is that you have the power to change that, and improve that code..

  3. CScout Compilation by allenw · · Score: 5, Insightful

    "The OpenSolaris kernel was a welcomed surprise: it was the only body of source code that did not require any extensions to CScout in order to compile."

    Given that the Solaris kernel has been compiled by two very different compilers (Sun Studio, of course, and gcc), it isn't that surprising. Because of the compiler issues, it is likely the most ANSI compliant of the bunch.

  4. statistical wash-out? by davejenkins · · Score: 4, Insightful

    If I am understanding correctly, you were looking for 'winners' and 'losers' (weasel words in and of themselves, but anyway...) in terms of 'quality' (another semi-subjective term that could make someone go crazy and drive motorcycles across the country for the rest of their lives).

    You found that '..the structure and internal quality attributes of a working, non-trivial software artifact will represent first and foremost the engineering requirements of its construction, with the influence of process being marginal, if any.' -- or in plain English: "the app specs had a much bigger influence when compared to internal efficiencies".

    I would wonder if you're just seeing a statistical wash-out. Are you dealing with data sets (tens of millions of lines and thousands of functions) that are so large, that patterns simply get washed out in the analysis?

    Oh dear, my post is no more clear than the summary...

  5. Re:Is it just me? by raddan · · Score: 4, Insightful

    It's not a very good summary, but the paper is well-written, which is interesting considering that the author is the one who submitted the summary to Slashdot. I suspect that he assumes we have more familiarity with the subject than we actually do.

  6. KLOCs? by Baavgai · · Score: 4, Insightful

    If good code and bad code were a simple automated analysis away, don't you think everyone would be doing it? What methodolgy could possibly give a quantitative weighting for "quality"?

    "To my surprise there was no clear winner or loser..." Not really a surprise at all, actually.

  7. Re:Is it just me? by Diomidis+Spinellis · · Score: 4, Insightful

    I didn't write the last part when I submitted the story, and, yes, the summary given here is comprehensible, because it appears out of context. What the sentence '..the structure and internal quality attributes of a working, non-trivial software artifact will represent first and foremost the engineering requirements of its construction, with the influence of process being marginal, if any.' means is that when you build something complex and demanding, say a dam or an operating system kernel, the end result will have a specific level of quality, no matter how you build it. For this reason the differences in the software built with a tightly-controlled proprietary software process and that built using an open-source process are not that big.

  8. Re:Is it just me? by legutierr · · Score: 5, Insightful

    How useful is it to write something about computers that needs to be translated for the slashdot audience? Jargon is a great way to provide specialized information to insiders quickly and efficiently, but this is slashdot. If slashdot readers need for you to restate your description of a problem or observation related to the Linux kernel (even if that description is taken out of context), could it be that the paper could be written in a more open manner? The quote you provided from your paper seems to speak to a narrow audience; how narrow must your audience be, however, if it excludes a good portion of slashdot's readers?

    If I seem overly critical, I do not mean to, it is only that I hate to see good, useful research made less accessible to non-academics by the use of academic language.