The 5th dwarf

Have to cook the turkey, so this one will be brief, have been working on a new tool, that ultimately will provide what ostra was capable of, ctracer, the new tool generates a kernel module that after built and loaded provides these preliminary results. Now to work on a not so lame relaying module for the trace information, such as the one in blktrace.

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  • Anonymous Coward  On January 19, 2007 at 7:47 pm

    Do you sometimes write comments in your code ? I don’t see any in ctracer.c. (License does nt count)

  • admin  On January 20, 2007 at 9:28 am

    My bad, will write some now.

  • Anonymous  On January 27, 2007 at 3:55 pm

    To what extent are you reinventing the wheel (systemtap) ?

  • admin  On January 27, 2007 at 6:00 pm

    Well, ctracer certainly is very, very close to systemtap in some regards, thing is my previous project, OSTRA, was not using kprobes, but using sparse to insert the hooks while building the kernel (or other projects), not the DWARF tags, and systemtap was just starting (or it started a while later, not sure right now), then I started working on pahole, just to find struct holes, the information I was getting from the DWARF tags seemed useful for other purposes, and then I thought about connecting the dwarves with, at least, ostra-cg, the tool that postprocesses the collected data to generate the callgraphs, thats when ctracer was born.

    I’m now studying systemtap and certainly will try to converge ideas and code I wrote in the dwarves and ideas developed in OSTRA.

    So there is overlapping and complementary functionality, having both flourishing is a good thing, I guess 🙂

  • Frank Ch. Eigler  On January 30, 2007 at 9:10 am

    You may find that if the data extraction variety and robustness needs
    start climbing, a more general framework like systemtap will justify
    itself. See for example here, which hints at what is required to give
    proper per-thread nesting.
    Or in-situ data filtering:


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