On 17-Apr 15:26, Suren Baghdasaryan wrote: > On Tue, Apr 2, 2019 at 3:42 AM Patrick Bellasi <patrick.bell...@arm.com> > wrote:
[...] > > Do not allow to change sched class specific params and non class > > specific params (i.e. clamp values) at the same time. This keeps things > > simple and still works for the most common cases since we are usually > > interested in just one of the two actions. > > Sorry, I can't find where you are checking to eliminate the > possibility of simultaneous changes to both sched class specific > params and non class specific params... Am I too tired or they are > indeed missing? No, you right... that limitation has been removed in v8 :) I'll remove the above paragraph in v9, thanks for spotting it. [...] > > +static int uclamp_validate(struct task_struct *p, > > + const struct sched_attr *attr) > > +{ > > + unsigned int lower_bound = p->uclamp_req[UCLAMP_MIN].value; > > + unsigned int upper_bound = p->uclamp_req[UCLAMP_MAX].value; > > + > > + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN) > > + lower_bound = attr->sched_util_min; > > + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) > > + upper_bound = attr->sched_util_max; > > + > > + if (lower_bound > upper_bound) > > + return -EINVAL; > > + if (upper_bound > SCHED_CAPACITY_SCALE) > > + return -EINVAL; > > + > > + return 0; > > +} [...] > > static void uclamp_fork(struct task_struct *p) > > { > > unsigned int clamp_id; > > @@ -1056,6 +1100,13 @@ static void __init init_uclamp(void) > > #else /* CONFIG_UCLAMP_TASK */ > > static inline void uclamp_rq_inc(struct rq *rq, struct task_struct *p) { } > > static inline void uclamp_rq_dec(struct rq *rq, struct task_struct *p) { } > > +static inline int uclamp_validate(struct task_struct *p, > > + const struct sched_attr *attr) > > +{ > > + return -ENODEV; > > ENOSYS might be more appropriate? Yep, agree, thanks! > > > +} > > +static void __setscheduler_uclamp(struct task_struct *p, > > + const struct sched_attr *attr) { } > > static inline void uclamp_fork(struct task_struct *p) { } > > static inline void init_uclamp(void) { } > > #endif /* CONFIG_UCLAMP_TASK */ > > @@ -4424,6 +4475,13 @@ static void __setscheduler_params(struct task_struct > > *p, > > static void __setscheduler(struct rq *rq, struct task_struct *p, > > const struct sched_attr *attr, bool keep_boost) > > { > > + /* > > + * If params can't change scheduling class changes aren't allowed > > + * either. > > + */ > > + if (attr->sched_flags & SCHED_FLAG_KEEP_PARAMS) > > + return; > > + > > __setscheduler_params(p, attr); > > > > /* > > @@ -4561,6 +4619,13 @@ static int __sched_setscheduler(struct task_struct > > *p, > > return retval; > > } > > > > + /* Update task specific "requested" clamps */ > > + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP) { > > + retval = uclamp_validate(p, attr); > > + if (retval) > > + return retval; > > + } > > + > > /* > > * Make sure no PI-waiters arrive (or leave) while we are > > * changing the priority of the task: [...] -- #include <best/regards.h> Patrick Bellasi