Re: How to hook a context switch??

From: Gromer (osIndgy_at_gmail.com)
Date: 10/23/05

  • Next message: Dirk Craeynest: "FINAL CFP, Reliable Software Technologies, Ada-Europe 2006" 
    Date: 23 Oct 2005 03:51:50 -0700

    Sorry the actual post was snipped off... below is pasted the actual
    one..

    Hi,

    I have one issue and would like to get some expert advise from the
    group. The below shown code snippet gives some idea about the scenario.
    I have basically one function (func_1) which does a wake_up after
    processing some information. Once the wake_up is executed the system
    crashes.

    So to debug this, i've put printks after the add_wait_queue() and
    schedule function to capture the functions that gets executed with a
    wake_up... but for no help.. Im unable to find the thread which gets
    executed after the wake_up.

    I'm wondering how to capture or debug which thread/function gets the
    CPU when this wake_up has been executed... Any pointer would be highly
    appreciable.

    How is such a situation usually debugged?? Can such a context switching
    be hooked..

    /* Wait on here when we're waiting device to be ready */
    wait_queue_head_t waitDev;

    void func_1( struct func_arg*)
    {

     /*..Do some useful work */

            wake_up(&waitDev); /* crash occurs here */

    }

    int sec_func (struct func_arg2 *)
    {

         /* some processing work done here */
                ....
                 ..
            set_current_state(TASK_UNINTERRUPTIBLE);
            add_wait_queue(&waitDev, &wait);
            spin_unlock(mutex);
            schedule();
            remove_wait_queue(&waitDev, &wait);
            spin_lock(chip->mutex);

          /* some more work is being done here */

    }

    Brendan wrote:
    > Hi,
    >
    > "Gromer" <osIndgy@gmail.com> wrote in message
    > news:1130052479.202415.126070@o13g2000cwo.googlegroups.com...
    > > Hi,
    > > Since i have'nt got any response for linux groups.. i'm posting it in
    > > this group.. Hopefully someone in this group can throw some light :)
    >
    > Considering that I'm reading this in alt.os.development, the first
    > thing I'd suggest is rewriting the entire OS to your liking. Starting
    > with a "hello world" kernel booted from GRUB seems to be a
    > popular way to begin. :-)
    >
    > On a more serious note, was there meant to be an attachment or
    > something? It's a little hard for anyone to debug code without
    > seeing it...
    >
    >
    > Cheers,
    >
    > Brendan

  • Next message: Dirk Craeynest: "FINAL CFP, Reliable Software Technologies, Ada-Europe 2006"

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