On Wed, Mar 07, 2018 at 11:38:52AM +0100, Peter Zijlstra wrote: > On Thu, Feb 22, 2018 at 05:01:53PM +0000, Patrick Bellasi wrote:
> > @@ -5218,7 +5242,7 @@ static inline void util_est_enqueue(struct cfs_rq > > *cfs_rq, > > > > /* Update root cfs_rq's estimated utilization */ > > enqueued = READ_ONCE(cfs_rq->avg.util_est.enqueued); > > - enqueued += _task_util_est(p); > > + enqueued += (_task_util_est(p) | 0x1); > > UTIL_EST_NEED_UPDATE_FLAG, although I do agree that 0x1 is much easier > to type ;-) > > But you set it for the cfs_rq value ?! That doesn't seem right. > > > WRITE_ONCE(cfs_rq->avg.util_est.enqueued, enqueued); > > } > > > > @@ -5310,7 +5334,7 @@ static inline void util_est_dequeue(struct cfs_rq > > *cfs_rq, > > if (cfs_rq->nr_running) { > > ue.enqueued = READ_ONCE(cfs_rq->avg.util_est.enqueued); > > ue.enqueued -= min_t(unsigned int, ue.enqueued, > > - _task_util_est(p)); > > + (_task_util_est(p) | > > UTIL_EST_NEED_UPDATE_FLAG)); > > } > > WRITE_ONCE(cfs_rq->avg.util_est.enqueued, ue.enqueued); > > OK, so you unconditionally set that bit here to make the add/sub match. Clearly I wasn't having a good day yesterday.