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Ask New 2.4 Maintainer Marcelo Tosatti Anything

Linus keeps hinting (declaring, even) that he's nearly ready to work full-time on the 2.5 development branch of his kernel, and hand the 2.4 kernel off to Marcelo Tosatti. Marcelo's graciously agreeed to answer questions (you might want to read some of his mailing list contributions first), so here's your chance to ask him what he'll do in the famous footsteps of Linus and Alan Cox, and how he got there. Please only put one question per post; we'll pass along the top-rated comments to Marcelo for his answers, and hear back from him shortly.

46 of 308 comments (clear)

  1. My Question by ekrout · · Score: 4, Interesting

    Will Alan Cox's choice to not unveil security changes in the kernel changelog potentially affect other developers?

    --

    If you celebrate Xmas, befriend me (538
  2. background by -tji · · Score: 5, Interesting

    For those of us not part of the kernel community, can you give us an overview of your background and past work done in the Linux world?

  3. Coup by ksw2 · · Score: 3, Offtopic

    Do you ever have strange, murky dreams about launching a major coup against the established leaders of the Linux kernel, surmounting their positions and establishing yourself as the all-time evil maniacal leader of Linux? (mwuhahaha)

  4. 2.4 and 2.5 by Anonymous Coward · · Score: 5, Interesting

    How much do you expect to be backported from 2.5? Obviously there's a lot of stuff people are interested in putting in the kernel, but should probably refine in a development kernel first (e.g. XFS, JFS, preemption, lowlatency, etc.)

  5. Money by bnatale · · Score: 4, Interesting

    Does someone pay you for working on linux, do you have another job where you can earn some money to buy food or do you have to beg on the mainstreet in your spare time?

    1. Re:Money by sg_oneill · · Score: 3, Interesting

      Noe *that* raises an interesting point. Since you are working at Concectiva (perhaps with Rik?) , what is your take on the Rik VM vs Andrea VM debate (largely resolved presumably) and is it even relevant anymore

      --
      Excuse the Unicode crap in my posts. That's an apostrophe, and slashdot is busted.
  6. Hit by a bus by moonboy · · Score: 5, Interesting



    I'd hate to stray from the status quo where standard interview questions are concerned, so in keeping with it, I ask:

    What's it like knowing that, if (God forbid) Linus and Alan were hit by a bus, you might be "The Man"?

    Hey, someone had to ask.

    --

    Co-founder and designer at Music Nearby: http://musicnearby.com
  7. Hardware to support in 2.4? by Lumpish+Scholar · · Score: 4, Interesting

    What hardware do you think will need additional support in the 2.4 branch? Big (>150G) hard disks? KT266A and/or nForce chipset motherboards? USB 2.0?

    --
    Stupid job ads, weird spam, occasional insight at
  8. Expectations by MikeBabcock · · Score: 5, Interesting

    In the time you've been aware of or been using Linux, how have your expectations for what it ought to be or eventually become changed? I know in the time I've used it I'd never expected it, for example, to become a desktop OS but rather a good server or embedded product. What did you expect when you first started with Linux, and what do you expect now?

    --
    - Michael T. Babcock (Yes, I blog)
  9. Age a question by debrain · · Score: 5, Interesting

    If what I've read is correct, you are the youngest maintainer for this kernel. Do you have any feelings on a social level, regarding much of the peer review and critism will come from people who are older? (and very possibly set in their ways, and potentially intimidating)

  10. Preemptile by bnatale · · Score: 4, Interesting

    Ok, here comes the question that everyone wants to have answered: When will the patches to make linux fully preemptile be included in the official kernel?

  11. security patches in the Changelogs? by LMCBoy · · Score: 4, Interesting

    Will you be following Alan Cox's lead by withholding security patch information from the kernel Changelogs?

    --
    Liberal (adj.): Free from bigotry; open to progress; tolerant of others.
  12. Threads by Exmet+Paff+Daxx · · Score: 5, Interesting

    What are your thoughts about threads? Specifically, do you support Linus's "Context of Execution" generality with clone() or are you going to focus more on plain POSIX pthreads compliance?

    Any chance of Alan Cox's multi-threaded post-mortem debugging patch which dumps multiple core files for each lightweight process (LWP) making it into the kernel? How about support for post mortem debugging of multithreaded core files in general (right now there is zero support).

    Any rants about threading as a general topic would work.

    --
    If guns kill people, then CmdrTaco's keyboard misspells words.
  13. Stability vs Features by azaroth42 · · Score: 5, Interesting
    How do you intend to decide which new patches should be added to 2.4, the stable tree, and which are not to be included as being more appropriate to just 2.5, the unstable development tree?
    For example, do new or updated device drivers rank more highly than VM updates?

    -- Azaroth

  14. How do you plan to handle the big companies? by hansendc · · Score: 5, Interesting

    As all of us know, many large companies are putting large amounts of resources toward Linux. 2.4 will continue to be important to these companies because it is the version currently being shipped with the distributions, and will continue to be shipped for at least a year or two.

    How are you going to deal with the submissions from people like IBM and SGI who are going to want to make significant changes to 2.4?

  15. Sound drivers by BlowCat · · Score: 5, Informative
    The sound drivers are very poorly written. A lot of code is duplicated. Not all drivers support some ioctls. Every driver has its peculiarities, e.g. some drivers reset dsp to mono, 8bit on DSP_RESET, some don't. Some support /dev/audio, some don't.

    Not having ALSA in 2.4.x means no good sound support in the stable kernel for another year of two. Do you plan to integrate ALSA into the 2.4 branch? If yes, will it happen after it's done on the 2.5 branch?

  16. Do you use a distribution? by martinde · · Score: 4, Interesting

    If you use a distribution, which one and why? How about a GUI environment? VI or emacs?

    1. Re:Do you use a distribution? by bfree · · Score: 5, Interesting

      To rewrite the above question the way I'd like it asked:

      What operating systems and platforms do you personally use and which ones do you also use (and why)?

      Do you run a common environment on all your machines (in as far as possible) or do you run different things in different places and which environments do you prefer for what?

      What development tools do you use (especially for the kernel), would you do anything differebtly for the kernel (like make it compile with other compilers) if you could (or will you) and would you like to (or will you) place the Linux stable kernel into CVS or another version control system?

      Do you feel any personal preferences for anything might actually be in anyway reflected in your work as the stable kernel maintainer?

      Do you have a good lawyer? Are you planing on travelling to the U.S.A. (for all I know you live there, excuse my ignorance:-)? Have you experience dealing with politicians, business leaders and large groups and do you see this as a part of your job description?

      When you stop maintaing the stable kernel, what would you like people to be saying about your reign?

      Linux or BSD :-)

      --

      Never underestimate the dark side of the Source

  17. Alan Cox and politics by melquiades · · Score: 5, Interesting

    Alan Cox's stand on the changelog is clearly not only a matter of personal protection, but a political statement. He has chosen an issue that is tremendously important to Linux, free software, and software developers everywhere, and certainly it's right for him to be pursuing it.

    But is the Linux kernel the right forum for politics? Do you feel that it's a bad idea to involve the kernel in politics -- a slippery slope in which the software itself becomes a political pawn? Or would you say that the kernel -- and all software -- has already become a political pawn, and Cox's actions are entirely justified given that free software's existence is under increasing threat?

  18. Human interest by ChrisJones · · Score: 4, Interesting

    What scares you the most about taking on this fairly hefty responsibility?

    --
    Chris "Ng" Jones
    cmsj@tenshu.net
    www.tenshu.net
  19. The Deal with Marcelo, Alan and Linus? by Zeio · · Score: 4, Interesting

    This is a mixed question/comment.

    What is going on here?

    It seems that Alan has stopped doing his -AC series...

    Linus is finishing up 2.4.X after making some deep changes to the VM (Adrea's new VM), and thankfully adding EXT3, but form what I have been reading, 2.4.15 is the end of the stable kernel series (with no XFS or JFS support which is upsetting).

    Andrea has a plethora of experimental/tweaked patches in ftp.kernel.org/pub/linux/kernel/people/andrea. What is interesting/worrisome to me is that Marcelo's directory there is empty.

    Marcelo must be a great guy, I've seen a lot of banter on newsgroups with him, and a few chages in the stable changelog here and there, but to me it looks like a lot of talk. Alan used to release (past tense, it seems it has stopped) AC patches on a near daily basis, to me, Marcelo is vapor.

    Is the maintainer's jobs simple to make small changes to the kernel when errata is found? Or is it, as Alan has done, to integrate and merge a LOT of stuff to produce a useful and robust hybrid kernel and then suggest that maybe the unbroken things should be merged in.

    I wish Marcelo luck in this endeavor, but also wish to see loads of "maintainence," Linux really, really needs feverish active development, and there a lot of people, Like Alan and Linus, who put out quite a bit. I am hoping Marcelo will set a new precedent for uber-feverish maintenance - maybe even see XFS and JFS and other things that the distributions have to waste huge amounts of time tinkering and adding various enterprise-ish things to make the Linux kernel stand up for, as they put it, prime time.

    --
    Legalize the constitution. Think for yourself question authority.
  20. Money by bribecka · · Score: 4, Interesting

    I'm assuming that maintaining the kernel is a volunteer, non-paying position. And since it takes money to live in this world, how do you find time to actually earn a living while keeping up with the kernel?

    --

    Where are we going and why am I in this handbasket?

  21. CML2, cvs, kdb, crypto and more by iamsure · · Score: 5, Interesting

    If during the course of your maintainership CML2 proves very successful (as I beleive it already has) would you consider using it instead of CML1?

    Also, would you consider moving crypto into the main tree in the near future? Debian has, Redhat will "soon"..

    Would you consider using bitkeeper, cvs, or even complete changelogs with proper attribution of WHICH merges took place?

    And finally, would you consider FINALLY bringing kdb into the main kernel? Linus doesnt want it, but he doesnt want it because he doesnt see the value. He didnt say he banned it..

  22. Patches by return+42 · · Score: 5, Interesting

    Linus likes very small patches, everything broken down into little chunks of functionality. Alan is ok with bigger patches. What do you like and dislike in the patches people send you?

  23. Linux in the Latin world? by The+Bungi · · Score: 4, Informative

    I know you work for a Brazilian company (Conectiva), though your name seems more Italian than not. Regarless, you are (along with Miguel de Icaza, who is from Mexico) probably the most visible non-european/american member of the Linux kernel development community. Do you have any plans to promote or push Linux as a viable alternative to government agencies or companies in Brazil or other Latin American countries?

  24. Why you? by CmdrPinkTaco · · Score: 5, Interesting

    This is not intended as a flame or a troll, more of an interview style question. I figure since we are the people who are putting our trust in this person to handle *our* kernel, that this should also be our chance to learn about the person responsible.

    What makes you think that you can handle maintaining the Linux Kernel? What qualifications do you have and why should we (the people) trust you with the Linux kernel.

    I realize that this is actually two questions, but they more or less go together in one answer.

    --
    Please give your mod points to others, Im at the cap. They will appreciate it more
  25. Interaction with distros by DaoudaW · · Score: 3, Interesting

    A number of distros are already using 2.4.x. I am curious how much of the maintenance of the 2.4 kernel will be simply incorporating changes already made by the different distros, how much will be making changes in response to distro requests, and how much of the process is independent from the distros?

  26. A pretty generic question by archen · · Score: 5, Interesting

    How do you view Linux in the scheme of things? Mainly where do you think the niche of Linux is now, and where will it be years from now. How do you view the direction Linux tends to be taking compared to other OS's (Windows XP, FreeBSD, etc) - ["direction" is up to what ever you personally interpret it to be BTW]

  27. Any plans to improve documenting the kernel? by Carnage4Life · · Score: 5, Interesting
    Currently the Linux kernel is filled with functions that are either poorly documented or completely undocumented. One of the purported benefits of Free Software is that many developers can jump in and help yet when you have functions like __free_pages_ok in page_alloc.c that are important, complex yet the only comment is

    Buddy system. Hairy. You really aren't expected to understand this.


    doesn't this somehow defeat the point of the source being available in the first place? Basically the question I have to ask is this, "I have flirted with the thought of sending comment only patches to the kernel to further help people understand certain subtleties (e.g. why the pprev and next pointers in user_struct are not what they seem) in the source code especially CS students who are learning about the kernel in operating systems classes. If someone were to start such a program would such patches be accepted into the kernel?
    1. Re:Any plans to improve documenting the kernel? by cymen · · Score: 3, Interesting

      How can something be impossible to document? If the person understands the problem well enough to write the code, they should be able to express the same thoughts and intentions in English comments.

      When you write code you write for a specific standard (or compiler or interpreter) but when you write English you write for unknown. Descriptions could at some point get more lengthy than code. Would that be bad? I don't know. I'd rather have the information than not, personally. But I can see why bibles of information are kept out of the kernel.

  28. code control by brer_rabbit · · Score: 5, Interesting

    Have you thought about putting your changes under some sort of version control software? If you started putting the kernel/patches under CVS, maybe the rest of the kernel crowd would follow.

    1. Re:code control by Erik+Hensema · · Score: 4, Insightful

      Subquestion: if you'd put the kernel under CVS, would you allow commit access to key developers?

      --

      This is your sig. There are thousands more, but this one is yours.

  29. National biases. by saintlupus · · Score: 3, Interesting

    In your experience, is the kernel development genuinely international and multilingual, or are there tensions between developers from different regions or who speak different native languages?

    --saint

  30. Conectiva & Kernel & Security by GdoL · · Score: 3, Interesting

    As a brazilian citizen (and Conectiva employee), will you be free to publish anything on the changelogs?

    --

    ------I can please only one person per day. Today is not your day. Tomorrow isn't looking good either.------
  31. cage match... by feldkamp · · Score: 5, Funny

    Who would win in a fight? You, Alan Cox, or Linus?

  32. Kernel growth -- is it a problem? by connorbd · · Score: 5, Interesting

    While I am a passionate Linux supporter, I have also come to the conclusion that kernel bloat is likely to be a major issue fairly soon. It appears to have been the case for some time that =486 systems Need Not Apply, and Red Hat in particular has become a rather memory-hungry distro (it won't even install on my 16MB Pentium system, though I doubt this is really a kernel issue). The end result is that Linux seems slowly to be growing out of the lower-end used-server-in-a-closet market that helped it get so big in the first place.

    My question: I presume kernel bloat, both in terms of code size and resource demands, can impact heavily on maintainability. Do you see this as a significant issue for the future, how much of a problem is it, and is it something that can be easily addressed without tearing apart the code base and reorganizing it from the ground up?

    /Brian

  33. diary by Lennie · · Score: 5, Interesting

    Do you have a diary, like Alan Cox we can read ?

    Because we all like to know, if you'll actually be doing what your gonna promise now :)

    --
    New things are always on the horizon
  34. list of changes for the common folk by e40 · · Score: 5, Insightful

    One thing that is really missing is a list of changes in each kernel release that is meant to be consumed by the masses. The "changelogs" that are offered up are sorely lacking for us non-kernel hackers. What I'd like to see is a prose description of the changes in each version. Something like Release notes for 2.2.18 by Alan Cox is a step in the right direction, but some of it is even a little too technical. For example, in the above document,

    set_current_state
    • Fixed potential SMP race
    means little to me and probably a lot of other people. Under what condition does this occur? The question why should I care about this change? should be answered for each entry.

    How do you feel about doing something like this?

  35. Age by FreakOfTheWeek · · Score: 3, Interesting

    How will you respond to criticism from the corporate world (most of whom don't understand what linux is, let alone a kernel), that "linux" is being maintained by an 18 year old?
    Do you think this will reflect badly on the image of linux? (as seen from IT decision makers)

  36. Too many questions for Marcelo - Ask Slashdot??? by tercero · · Score: 4, Funny

    After the interview is all said and done. That's only ~10 questions. I'm seeing a lot more than 10 very important (IMHO) questions. Some of these questions being unanswered is a big contributor to why Linux is not so readily accepted in the corporate world.

    Where can we get the questions answered? I think that there ought to be a Linux kernel documentation project to bring the docs up to speed and answer questions like this. I have not the knowledge of the kernel for this, but such a project would be invaluable to the Linux community.

  37. Boot Messsages by x00 · · Score: 3, Interesting

    Linus has stated that he'd like to get rid of a lot of the "non-informational" messages on boot and with this I have to agree with him.

    Do you plan on furthering this cause, and helping make our boot times a simpler, less complicated read?

    --
    May contain traces of nut.
  38. You are an encouragement to 18 yr olds everywhere! by danpbrowning · · Score: 4, Offtopic

    Marcelo,

    I must say that you are an amazing yet rare individual, to have commanded that much respect at the age of 18. Wow. I can't handle OS design now, let alone when I was 18. Would you be so kind as to share some about your upbringing, environment, faith, or other factors that were beneficial to you in making you who you are today?

    Thank you,

    --
    Daniel
  39. girls running to you yet? by 2Bits · · Score: 4, Funny

    Now that you are suddenly famous, do you see a lot of girls flocking to you yet?

  40. Features vs Stability by spudgun · · Score: 3, Interesting

    Do you intend to bend to popular demand for features at the price of stability or is stability king in the stable kernel ?

    --
    Type unto others as you would have them type unto you.
  41. Am I too late? by GauteL · · Score: 3, Redundant

    I looked over some questions, and there are a couple of pretty obvious ones that either aren't their, or hidden due to that pesky moderation.

    For instance:
    1. The "lousy magazine"-question: Who would you rather be stuck with on a desert island?

    2. The "bitter old sysadmin"-question: You are 18, do you punk even know what Multics or VMS is?

    3. The "trick"-question: what do you prefer, emacs or vi? (trick question because we all know emacs is superior).

  42. Conectiva issues by Stonehead · · Score: 4, Interesting

    Is Conectiva going to let you spend all your time to the 2.4 kernel?
    I read that you live in the same house as Rik van Riel, who wrote the first Linux 2.4 VM and who also works for Conectiva. Rik wrote in his not-that-very-often updated diary that he travelled a lot in Brazil, to help customers anywhere. That takes a lot of time. Is your job going to be different once Alan Cox passes the maintainership?