Messages in this thread | | | Date | Fri, 14 Sep 2018 13:52:17 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v4 03/16] sched/core: uclamp: add CPU's clamp groups accounting |
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On Fri, Sep 14, 2018 at 10:07:51AM +0100, Patrick Bellasi wrote: > On 13-Sep 21:12, Peter Zijlstra wrote: > > On Tue, Aug 28, 2018 at 02:53:11PM +0100, Patrick Bellasi wrote: > > > +static inline void uclamp_cpu_get_id(struct task_struct *p, > > > + struct rq *rq, int clamp_id) > > > +{ > > > + struct uclamp_group *uc_grp; > > > + struct uclamp_cpu *uc_cpu; > > > + int clamp_value; > > > + int group_id; > > > + > > > + /* Every task must reference a clamp group */ > > > + group_id = p->uclamp[clamp_id].group_id; > > > > > +} > > > + > > > +static inline void uclamp_cpu_put_id(struct task_struct *p, > > > + struct rq *rq, int clamp_id) > > > +{ > > > + struct uclamp_group *uc_grp; > > > + struct uclamp_cpu *uc_cpu; > > > + unsigned int clamp_value; > > > + int group_id; > > > + > > > + /* New tasks don't have a previous clamp group */ > > > + group_id = p->uclamp[clamp_id].group_id; > > > + if (group_id == UCLAMP_NOT_VALID) > > > + return; > > > > *confused*, so on enqueue they must have a group_id, but then on dequeue > > they might no longer have? > > Why not ?
That's what it says on the tin, right? enqueue: "every task must reference clamp group" while on dequeue: "new tasks don't have a (previous) clamp group" and we check for NOT_VALID.
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