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    SubjectRe: [PATCH] sched: Make nr_uninterruptible count a signed value
    On 05/09/2012 06:46 AM, Diwakar Tundlam wrote:

    >> No that's right. nr_uninterruptible counts the number of tasks in
    >> uninterruptible sleep, so deactivate_task puts a task to sleep, so we
    >> need to increment the number of sleeping tasks, activate_task wakes a
    >> task up so we need to decrement the number of sleeping tasks.
    >
    > Yep, I looked at the code for task_contributes_to_load() and I understand what it is all about.
    > The ++ and -- are correct, I see it now.
    >
    > On the -ve values, strangely inspite of %Ld in the print statement, in my kernel, I see high unsigned values instead of -ve values for nr_uninterruptible.
    >
    > But the sum is always 0, though.
    >
    > Maybe it is an artifact of 32-bit machine displaying 64-bit print format.
    > An (unsigned long)(-24) promoted to (signed long long) ends up as 4294967272.
    > As seen in my output of sched_debug.


    This may do some help.

    Regards,
    Michael Wang
    ---
    kernel/sched/debug.c | 2 +-
    1 files changed, 1 insertions(+), 1 deletions(-)

    diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
    index 09acaa1..ab9d53f 100644
    --- a/kernel/sched/debug.c
    +++ b/kernel/sched/debug.c
    @@ -270,7 +270,7 @@ static void print_cpu(struct seq_file *m, int cpu)
    rq->load.weight);
    P(nr_switches);
    P(nr_load_updates);
    - P(nr_uninterruptible);
    + P((signed long)nr_uninterruptible);
    PN(next_balance);
    P(curr->pid);
    PN(clock);
    --
    1.7.4.1


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