lkml.org 
[lkml]   [2009]   [Aug]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: Tracing thread name
    * Matthieu CASTET (matthieu.castet@parrot.com) wrote:
    > Hi Mathieu,
    >
    > Mathieu Desnoyers a écrit :
    > > * Matthieu CASTET (matthieu.castet@parrot.com) wrote:
    > >> Hi,
    > >>
    > >> I use ltt on a 2.6.27 on an arm architecture.
    > >> It works quite well, but I have a minor problem :
    > >>
    > >> my application sets thread name with prctl PR_SET_NAME. But ltt viewer
    > >> doesn't seem to saw it.
    > >>
    > >
    > > Hrm, I guess we might want to instrument set_task_comm as you propose to
    > > get the correct process name, but if this gets us the thread name, I
    > > think it's only an implementation side-effect:
    >
    > > The way LTTng handles thread names is by adding a userspace "thread
    > > branding" event. It should be executed at thread startup. The downside
    > > of the current LTTng approach is that we cannot know the name of threads
    > > already executing before we started tracing.
    > >
    >
    > Do you know if it is possible to patch my version to add such feature ?
    >
    > I saw that the name already change in the trace before/after an exec.
    > How lltv get the new name ?
    > With "fs.exec" tracepoint ?
    > In that case I could fake a "fs.exec" tracepoint in set_task_comm.

    A better solution : you add a new event in both lttng and lttv, and
    modify state.c to support your new event. The current event to brand
    thread is named "userspace.thread_brand". Look for this in LTTV to see
    all the sites that need to support the new event (there are very few).

    Mathieu

    >
    > Thanks
    >
    > Matthieu
    >

    --
    Mathieu Desnoyers
    OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2009-08-04 15:07    [W:0.032 / U:32.124 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site