Re: test6-lowlatency-D1 results: 50msec + hangs ....

From: Philipp Rumpf (prumpf@parcelfarce.linux.theplanet.co.uk)
Date: Sat Aug 05 2000 - 20:43:04 EDT

  • Next message: David S. Miller: "Re: test6-lowlatency-D1 results: 50msec + hangs ...."

    On Sat, Aug 05, 2000 at 09:16:55PM +0200, Benno Senoner wrote:
    > Hi,
    >
    > here the results of Ingo's lowlatency-test6-pre2-D1 patch:
    >
    > to mention that I had to remove these two lines in
    > /drivers/char/pc_keyb.c:
    >
    > if (!spin_is_locked(&kbd_controller_lock))
    > BUG();

    That's bogus on UP (spin_is_locked always returns 0).

    I think it would be reasonably nice to have something like

    spin_lock_held(spinlock_t *lock);

    that returns 1 for UP and spin_is_locked(lock) for SMP - basically

    foo()
    {
            if (!spin_lock_held(&foo_lock))
                    BUG();

            ...
    }

    looks to me like it'll avoid errors more effectively than

    /* Call with foo_lock held */
    foo()
    {
            ...
    }

            Philipp Rumpf

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.rutgers.edu
    Please read the FAQ at http://www.tux.org/lkml/

    This archive was generated by hypermail 2b29 : Sat Aug 05 2000 - 20:48:02 EDT