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    SubjectRe: [PATCH 2/2] sched: Fix "divide error: 0000" in find_busiest_group
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    On Tue, 2011-07-19 at 14:58 -0600, Terry Loftin wrote:
    > Add a check to sched_avg_update() to detect and reset age_stamp if the
    > clock value has wrapped. Because __cycles_2_ns() includes an offset
    > to account for start up time, the clock may not wrap to zero, so use
    > the current clock value instead.

    So you're running on a platform (unspecified) where we use a raw
    sched_clock() that is buggy. Again, you're fixing symptoms not causes.

    > Signed-off-by: Terry Loftin <terry.loftin@hp.com>
    > Signed-off-by: Bob Montgomery <bob.montgomery@hp.com>
    > ---
    > diff --git a/kernel/sched.c b/kernel/sched.c
    > index 18d38e4..b39cae1 100644
    > --- a/kernel/sched.c
    > +++ b/kernel/sched.c
    > @@ -1256,6 +1256,8 @@ static void sched_avg_update(struct rq *rq)
    > {
    > s64 period = sched_avg_period();
    >
    > + if (unlikely(rq->age_stamp > rq->clock))
    > + rq->age_stamp = rq->clock;
    > while ((s64)(rq->clock - rq->age_stamp) > period) {
    > /*
    > * Inline assembly required to prevent the compiler





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