On Tue, Aug 28, 2018 at 02:53:10PM +0100, Patrick Bellasi wrote: > static inline int __setscheduler_uclamp(struct task_struct *p, > const struct sched_attr *attr)
But large for inline now. > { > + int group_id[UCLAMP_CNT] = { UCLAMP_NOT_VALID }; > + int lower_bound, upper_bound; > + struct uclamp_se *uc_se; > + int result = 0; I think the thing would become much more readable if you set lower/upper_bound right here. > > + mutex_lock(&uclamp_mutex); > > + /* Find a valid group_id for each required clamp value */ > + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN) { > + upper_bound = (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) > + ? attr->sched_util_max > + : p->uclamp[UCLAMP_MAX].value; > + > + if (upper_bound == UCLAMP_NOT_VALID) > + upper_bound = SCHED_CAPACITY_SCALE; > + if (attr->sched_util_min > upper_bound) { > + result = -EINVAL; > + goto done; > + } > + > + result = uclamp_group_find(UCLAMP_MIN, attr->sched_util_min); > + if (result == -ENOSPC) { > + pr_err(UCLAMP_ENOSPC_FMT, "MIN"); AFAICT this is an unpriv part of the syscall; and you can spam the log without limits. Not good. > + goto done; > + } > + group_id[UCLAMP_MIN] = result; > + } > + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) { > + lower_bound = (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN) > + ? attr->sched_util_min > + : p->uclamp[UCLAMP_MIN].value; > + > + if (lower_bound == UCLAMP_NOT_VALID) > + lower_bound = 0; > + if (attr->sched_util_max < lower_bound || > + attr->sched_util_max > SCHED_CAPACITY_SCALE) { > + result = -EINVAL; > + goto done; > + } > + > + result = uclamp_group_find(UCLAMP_MAX, attr->sched_util_max); > + if (result == -ENOSPC) { > + pr_err(UCLAMP_ENOSPC_FMT, "MAX"); > + goto done; > + } > + group_id[UCLAMP_MAX] = result; > + } > + > + /* Update each required clamp group */ > + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN) { > + uc_se = &p->uclamp[UCLAMP_MIN]; > + uclamp_group_get(UCLAMP_MIN, group_id[UCLAMP_MIN], > + uc_se, attr->sched_util_min); > + } > + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) { > + uc_se = &p->uclamp[UCLAMP_MAX]; > + uclamp_group_get(UCLAMP_MAX, group_id[UCLAMP_MAX], > + uc_se, attr->sched_util_max); > + } > + > +done: > + mutex_unlock(&uclamp_mutex); > + > + return result; > +}