normal scheduling policy and absolute bandwidth allocation model for
realtime scheduling policy.
+Cycles distribution is based, by default, on a temporal base and it
+does not account for the frequency at which tasks are executed.
+The (optional) utilization clamping support allows to enforce a minimum
+bandwidth, which should always be provided by a CPU, and a maximum bandwidth,
+which should never be exceeded by a CPU.
+
WARNING: cgroup2 doesn't yet support control of realtime processes and
the cpu controller can only be enabled when all RT processes are in
the root cgroup. Be aware that system management software may already
$PERIOD duration. "max" for $MAX indicates no limit. If only
one number is written, $MAX is updated.
+ cpu.util.min
+ A read-write single value file which exists on non-root cgroups.
+ The default is "0", i.e. no bandwidth boosting.
+
+ The minimum utilization in the range [0, 1023].
+
+ This interface allows reading and setting minimum utilization clamp
+ values similar to the sched_setattr(2). This minimum utilization
+ value is used to clamp the task specific minimum utilization clamp.
+
+ cpu.util.max
+ A read-write single value file which exists on non-root cgroups.
+ The default is "1023". i.e. no bandwidth clamping
+
+ The maximum utilization in the range [0, 1023].
+
+ This interface allows reading and setting maximum utilization clamp
+ values similar to the sched_setattr(2). This maximum utilization
+ value is used to clamp the task specific maximum utilization clamp.
Memory
------
uclamp_group_put(clamp_id, prev_group_id);
}
+#ifdef CONFIG_UCLAMP_TASK_GROUP
+/**
+ * init_uclamp_sched_group: initialize data structures required for TG's
+ * utilization clamping
+ */
+static inline void init_uclamp_sched_group(void)
+{
+ struct uclamp_map *uc_map;
+ struct uclamp_se *uc_se;
+ int group_id;
+ int clamp_id;
+
+ /* Root TG's is statically assigned to the first clamp group */
+ group_id = 0;
+
+ /* Initialize root TG's to default (none) clamp values */
+ for (clamp_id = 0; clamp_id < UCLAMP_CNT; ++clamp_id) {
+ uc_map = &uclamp_maps[clamp_id][0];
+
+ /* Map root TG's clamp value */
+ uclamp_group_init(clamp_id, group_id, uclamp_none(clamp_id));
+
+ /* Init root TG's clamp group */
+ uc_se = &root_task_group.uclamp[clamp_id];
+ uc_se->value = uclamp_none(clamp_id);
+ uc_se->group_id = group_id;
+
+ /* Attach root TG's clamp group */
+ uc_map[group_id].se_count = 1;
+ }
+}
+
+/**
+ * alloc_uclamp_sched_group: initialize a new TG's for utilization clamping
+ * @tg: the newly created task group
+ * @parent: its parent task group
+ *
+ * A newly created task group inherits its utilization clamp values, for all
+ * clamp indexes, from its parent task group.
+ * This ensures that its values are properly initialized and that the task
+ * group is accounted in the same parent's group index.
+ *
+ * Return: 0 on error
+ */
+static inline int alloc_uclamp_sched_group(struct task_group *tg,
+ struct task_group *parent)
+{
+ struct uclamp_se *uc_se;
+ int clamp_id;
+
+ for (clamp_id = 0; clamp_id < UCLAMP_CNT; ++clamp_id) {
+ uc_se = &tg->uclamp[clamp_id];
+
+ uc_se->value = parent->uclamp[clamp_id].value;
+ uc_se->group_id = UCLAMP_NOT_VALID;
+ }
+
+ return 1;
+}
+#else /* CONFIG_UCLAMP_TASK_GROUP */
+static inline void init_uclamp_sched_group(void) { }
+static inline int alloc_uclamp_sched_group(struct task_group *tg,
+ struct task_group *parent)
+{
+ return 1;
+}
+#endif /* CONFIG_UCLAMP_TASK_GROUP */
+
static inline int __setscheduler_uclamp(struct task_struct *p,
const struct sched_attr *attr)
{
raw_spin_lock_init(&uc_map[group_id].se_lock);
}
}
+
+ init_uclamp_sched_group();
}
#else /* CONFIG_UCLAMP_TASK */
static inline void uclamp_cpu_get(struct rq *rq, struct task_struct *p) { }
static inline void uclamp_cpu_put(struct rq *rq, struct task_struct *p) { }
+static inline int alloc_uclamp_sched_group(struct task_group *tg,
+ struct task_group *parent)
+{
+ return 1;
+}
static inline int __setscheduler_uclamp(struct task_struct *p,
const struct sched_attr *attr)
{
if (!alloc_rt_sched_group(tg, parent))
goto err;
+ if (!alloc_uclamp_sched_group(tg, parent))
+ goto err;
+
return tg;
err:
sched_move_task(task);
}
+#ifdef CONFIG_UCLAMP_TASK_GROUP
+static int cpu_util_min_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 min_value)
+{
+ struct task_group *tg;
+ int ret = -EINVAL;
+
+ if (min_value > SCHED_CAPACITY_SCALE)
+ return -ERANGE;
+
+ mutex_lock(&uclamp_mutex);
+ rcu_read_lock();
+
+ tg = css_tg(css);
+ if (tg->uclamp[UCLAMP_MIN].value == min_value) {
+ ret = 0;
+ goto out;
+ }
+ if (tg->uclamp[UCLAMP_MAX].value < min_value)
+ goto out;
+
+out:
+ rcu_read_unlock();
+ mutex_unlock(&uclamp_mutex);
+
+ return ret;
+}
+
+static int cpu_util_max_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 max_value)
+{
+ struct task_group *tg;
+ int ret = -EINVAL;
+
+ if (max_value > SCHED_CAPACITY_SCALE)
+ return -ERANGE;
+
+ mutex_lock(&uclamp_mutex);
+ rcu_read_lock();
+
+ tg = css_tg(css);
+ if (tg->uclamp[UCLAMP_MAX].value == max_value) {
+ ret = 0;
+ goto out;
+ }
+ if (tg->uclamp[UCLAMP_MIN].value > max_value)
+ goto out;
+
+out:
+ rcu_read_unlock();
+ mutex_unlock(&uclamp_mutex);
+
+ return ret;
+}
+
+static inline u64 cpu_uclamp_read(struct cgroup_subsys_state *css,
+ enum uclamp_id clamp_id)
+{
+ struct task_group *tg;
+ u64 util_clamp;
+
+ rcu_read_lock();
+ tg = css_tg(css);
+ util_clamp = tg->uclamp[clamp_id].value;
+ rcu_read_unlock();
+
+ return util_clamp;
+}
+
+static u64 cpu_util_min_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return cpu_uclamp_read(css, UCLAMP_MIN);
+}
+
+static u64 cpu_util_max_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return cpu_uclamp_read(css, UCLAMP_MAX);
+}
+#endif /* CONFIG_UCLAMP_TASK_GROUP */
+
#ifdef CONFIG_FAIR_GROUP_SCHED
static int cpu_shares_write_u64(struct cgroup_subsys_state *css,
struct cftype *cftype, u64 shareval)
.read_u64 = cpu_rt_period_read_uint,
.write_u64 = cpu_rt_period_write_uint,
},
+#endif
+#ifdef CONFIG_UCLAMP_TASK_GROUP
+ {
+ .name = "util.min",
+ .read_u64 = cpu_util_min_read_u64,
+ .write_u64 = cpu_util_min_write_u64,
+ },
+ {
+ .name = "util.max",
+ .read_u64 = cpu_util_max_read_u64,
+ .write_u64 = cpu_util_max_write_u64,
+ },
#endif
{ } /* Terminate */
};
.seq_show = cpu_max_show,
.write = cpu_max_write,
},
+#endif
+#ifdef CONFIG_UCLAMP_TASK_GROUP
+ {
+ .name = "util_min",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .read_u64 = cpu_util_min_read_u64,
+ .write_u64 = cpu_util_min_write_u64,
+ },
+ {
+ .name = "util_max",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .read_u64 = cpu_util_max_read_u64,
+ .write_u64 = cpu_util_max_write_u64,
+ },
#endif
{ } /* terminate */
};
projects / platform / kernel / linux-exynos.git / commitdiff