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Kernel Tracing With LTTng On Ubuntu Maverick

Posted by kdawson on from the truth-of-kernel dept.

francis-giraldeau writes "Linux Tracing Toolkit (LTTng) provides high-performance kernel tracing for Linux. This is the killer app for system level debugging and performance tuning. It's now easier than ever to install, with packages released for Ubuntu Maverick. The short introduction to kernel tracing shows how to interpret a simple kernel trace and relate it to strace. I would like to ask Slashdot readers what they would expect as features for a kernel tracing analysis tool, because I'm starting my PhD on this topic and looking for ideas. Also, I wonder why LTTng is not mainline yet. Will Linus Torvalds see the light in 2011?"

11 of 88 comments (clear)

  1. Goal of the PhD work? by Anonymous Coward · · Score: 3, Insightful

    What is the goal of your work? Do you want to compare kernel tracing solutions and identify critical features in the process of coming up with a reasonable taxonomy? Do you want to implement something? Do you have a specific application for kernel tracing (e.g. informing performance tuning measures in enterprise environments which would probably be of interest to businesses)? Just throwing together a list of desired features is not going to be of interest to anyone, I guess. You have to come up with a motivation for each of the features, argue why this feature is necessary for the application at hand or for any application of kernel tracing in general, cite literature that gives evidence for your assumptions and conclusions. Maybe if you told the people what kind of work you're interested in and what the interest of your advisor(s) is, in which reasearch context (department, university) you are working, they could make sensible suggestions as to which features might be interesting to you.

    1. Re:Goal of the PhD work? by francis-giraldeau · · Score: 4, Informative

      Kernel tracing instrumentation is ready, now we need decent analysis tools. The problem is that there is so much data, that it's hard to interpret them. For the project, I have to come up with something that is new and better that what is already known. For example, we could get a better analysis than bootchart, or auto detect bottlenecks in a system (disk, CPU, memory, network, etc...). There are some work done to integrate userspace and kernel space tracing, virtual machine and host traces, dynamic and static trace points. For a distro, they could record a trace in background and send this information allong with the core dump when an application crash occur. That's all ideas!

  2. Re:Crowd-sourcing a degree... by maxwell+demon · · Score: 3, Insightful

    Well, I guess his PhD would not be about imagining those features, but about implementing them. He asked for ideas what to implement, not for ideas how to implement it.

    --
    The Tao of math: The numbers you can count are not the real numbers.
  3. Re:Crowd-sourcing a degree... by francis-giraldeau · · Score: 5, Insightful

    The reason is that I would like to make my research useful for tracing users, and I think the best way to do it is to ask people what they really need. I will give credits to those how helped my, why not? ;-)

  4. That it is safe to use in a production environment by Dug · · Score: 5, Insightful
    Not that much point having a tracing tool if an inexperienced admin cannot safely use it on a live system which has a problem.

    A problem already solved with DTrace on Solaris http://docs.sun.com/app/docs/doc/817-6223

  5. Ubuntu Only? by hduff · · Score: 3, Insightful

    Why does the OP mention the Ubuntu package when the project releases a tarball?

    There is no need to make news distro-centric when it does not need to be. The submitter should check to see what other binary packages are available or not mention them at all.

    --
    "I believe in Karma. That means I can do bad things to people all day long and I assume they deserve it." : Dogbert
    1. Re:Ubuntu Only? by compudj · · Score: 3, Informative

      So far, LTTng has been mainly integrated in embedded distros: WindRiver Linux, Montavista Linux and STLinux currently ship with LTTng. The interesting news that is particular about Ubuntu here is that, by installing the LTTng packages from PPA, it is now possible to easily deploy the LTTng kernel and userspace tracers on a desktop-oriented distribution.

  6. See the light? by codegen · · Score: 4, Insightful

    Maybe I'm reading slashdot too early on a weekend morning, but I find the last statement of the summary particularly offensive. It seems like everyone who has some sort of kernel widget wants a PR campaign to get it included in the mainline. How about you finish your Ph. D. first and provide some convincing evidence as to why every single person running Linux has to have the tool? The trace tools are available as a package for anyone who wants them now. Why should the mainline be burdened with maintaining the package unless a significant number of users need it?

    --
    Atlas stands on the earth and carries the celestial sphere on his shoulders.
    1. Re:See the light? by Anonymous Coward · · Score: 3, Insightful

      "if Linux wants to be taken seriously..."

      Funny the one thing needed to be taken seriously is, by magic, the subject of your thesis.

      Had you been working on, say, resizable ramdisks (I'm just making this up), then resizable ramdisks would have been the one thing needed in Linux for Linux to be taken seriously.

      Ever considered humility?

  7. Some googling by diegocg · · Score: 4, Insightful

    Also, I wonder why LTTng is not mainline yet

    Well, a bit of searching would have answered your question

    The LTTng maintainer has been working for months (years?) to get the kernel tracing into a decent shape. These days the Linux tracing support is wonderful, and not just for LTT - perf, ftrace and systemtap are awesome tools (and more powerful than LTTng in some ways). In fact perf can do all what the web page says and it seems to be more simple for my taste

  8. Re:That it is safe to use in a production environm by Dug · · Score: 5, Interesting

    "Not that much point having a tracing tool if an inexperienced admin cannot safely use it on a live system which has a problem. "

    Right. Because everyone knows the best place to develop, debug, and profile code is on a production machine, and the person doing the development should be a system administrator, preferably with minimal experience.

    I would say many people do know that the best place to understand the performance of a system in production is in production. If the vendors support techs can give an admin commands to run and know that a typo here or there will not result in a panic then that is a very useful feature.