[PATCH 2/2] sched: group nice

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

[-- Attachment #1: sched-group-nice.patch --]
[-- Type: text/plain, Size: 1769 bytes --]

allow to use nice values to set group weights

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
 kernel/sched.c |   39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

Index: linux-2.6/kernel/sched.c
===================================================================
--- linux-2.6.orig/kernel/sched.c
+++ linux-2.6/kernel/sched.c
@@ -8558,6 +8558,17 @@ static inline void unregister_fair_sched
 {
 	list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list);
 }
+
+static int cpu_nice_write(struct cgroup *cgrp, struct cftype *cftype,
+			  s64 niceval)
+{
+	return sched_group_set_nice(cgroup_tg(cgrp), niceval);
+}
+
+static s64 cpu_nice_read(struct cgroup *cgrp, struct cftype *cftype)
+{
+	return sched_group_nice(cgroup_tg(cgrp));
+}
 #else /* !CONFG_FAIR_GROUP_SCHED */
 static inline void free_fair_sched_group(struct task_group *tg)
 {
@@ -8867,6 +8878,29 @@ unsigned long sched_group_weight(struct 
 {
 	return tg->weight;
 }
+
+static int sched_group_set_nice(struct task_group *tg, int nice)
+{
+	unsigned int prio = nice + 20;
+
+	if (prio > ARRAY_SIZE(prio_to_weight))
+		return -EINVAL;
+
+	sched_group_set_weight(tg, prio_to_weight[prio]);
+	return 0;
+}
+
+static int sched_group_nice(struct task_group *tg)
+{
+	unsigned long weight = sched_group_weight(tg);
+	int prio;
+
+	for (prio = 0; prio < ARRAY_SIZE(prio_to_weight); prio++)
+		if (prio_to_weight[prio] <= weight)
+			break;
+
+	return prio - 20;
+}
 #endif
 
 #ifdef CONFIG_RT_GROUP_SCHED
@@ -9233,6 +9267,11 @@ static struct cftype cpu_files[] = {
 		.read_u64 = cpu_weight_read_u64,
 		.write_u64 = cpu_weight_write_u64,
 	},
+	{
+		.name = "nice",
+		.read_s64 = cpu_nice_read,
+		.write_s64 = cpu_nice_write,
+	},
 #endif
 #ifdef CONFIG_RT_GROUP_SCHED
 	{

--