Deal with task-groups whose bandwidth hasnt been explicitly set by the
administrator. Unallocated CPU bandwidth is equally distributed among such
"don't care" groups.
Signed-off-by : Srivatsa Vaddagiri <[email protected]>
include/linux/sched.h | 2 -
kernel/sched.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 79 insertions(+), 5 deletions(-)
diff -puN kernel/sched.c~cpu_ctlr_handle_dont_cares kernel/sched.c
--- linux-2.6.18-rc3/kernel/sched.c~cpu_ctlr_handle_dont_cares 2006-08-04 08:20:53.000000000 +0530
+++ linux-2.6.18-rc3-root/kernel/sched.c 2006-08-04 08:31:38.000000000 +0530
@@ -227,6 +227,12 @@ static DEFINE_PER_CPU(struct task_grp_rq
/* task-group object - maintains information about each task-group */
struct task_grp {
int ticks; /* bandwidth given to the task-group */
+ int left_over_pct;
+ int total_dont_care_grps;
+ int dont_care; /* Does this group care for its bandwidth ? */
+ struct task_grp *parent;
+ struct list_head dont_care_list;
+ struct list_head list;
struct task_grp_rq *rq[NR_CPUS]; /* runqueue pointer for every cpu */
};
@@ -6922,6 +6928,12 @@ void __init sched_init(void)
int i, j, k;
init_task_grp.ticks = -1; /* Unlimited bandwidth */
+ init_task_grp.left_over_pct = 100; /* 100% unallocated bandwidth */
+ init_task_grp.parent = NULL;
+ init_task_grp.total_dont_care_grps = 1; /* init_task_grp itself */
+ init_task_grp.dont_care = 1;
+ INIT_LIST_HEAD(&init_task_grp.dont_care_list);
+ list_add_tail(&init_task_grp.list, &init_task_grp.dont_care_list);
for_each_possible_cpu(i) {
struct prio_array *array;
@@ -7076,10 +7088,33 @@ void set_curr_task(int cpu, struct task_
#ifdef CONFIG_CPUMETER
+/* Distribute left over bandwidth equally to all "dont care" task groups */
+static void recalc_dontcare(struct task_grp *tg_root)
+{
+ int ticks;
+ struct list_head *entry;
+
+ if (!tg_root->total_dont_care_grps)
+ return;
+
+ ticks = ((tg_root->left_over_pct /
+ tg_root->total_dont_care_grps) * 5 * HZ) / 100;
+
+ list_for_each(entry, &tg_root->dont_care_list) {
+ struct task_grp *tg;
+ int i;
+
+ tg = list_entry(entry, struct task_grp, list);
+ tg->ticks = ticks;
+ for_each_possible_cpu(i)
+ tg->rq[i]->ticks = tg->ticks;
+ }
+}
+
/* Allocate runqueue structures for the new task-group */
-void *sched_alloc_group(void)
+void *sched_alloc_group(void *grp_parent)
{
- struct task_grp *tg;
+ struct task_grp *tg, *tg_parent = (struct task_grp *)grp_parent;
struct task_grp_rq *tgrq;
int i;
@@ -7088,6 +7123,11 @@ void *sched_alloc_group(void)
return NULL;
tg->ticks = -1; /* No limit */
+ tg->parent = tg_parent;
+ tg->dont_care = 1;
+ tg->left_over_pct = 100;
+ tg->ticks = -1; /* No limit */
+ INIT_LIST_HEAD(&tg->dont_care_list);
for_each_possible_cpu(i) {
tgrq = kzalloc(sizeof(*tgrq), GFP_KERNEL);
@@ -7097,6 +7137,15 @@ void *sched_alloc_group(void)
task_grp_rq_init(tgrq, tg->ticks);
}
+ if (tg->parent) {
+ tg->parent->total_dont_care_grps++;
+ list_add_tail(&tg->list, &tg->parent->dont_care_list);
+ recalc_dontcare(tg->parent);
+ } else {
+ tg->total_dont_care_grps = 1;
+ list_add_tail(&tg->list, &tg->dont_care_list);
+ }
+
return (void *)tg;
oom:
while (i--)
@@ -7109,9 +7158,18 @@ oom:
/* Deallocate runqueue structures */
void sched_dealloc_group(void *grp)
{
- struct task_grp *tg = (struct task_grp *)grp;
+ struct task_grp *tg = (struct task_grp *)grp, *tg_root = tg->parent;
int i;
+ if (!tg_root)
+ tg_root = tg;
+
+ if (tg->dont_care) {
+ tg_root->total_dont_care_grps--;
+ list_del(&tg->list);
+ recalc_dontcare(tg_root);
+ }
+
for_each_possible_cpu(i)
kfree(tg->rq[i]);
@@ -7121,14 +7179,27 @@ void sched_dealloc_group(void *grp)
/* Assign quota to this group */
void sched_assign_quota(void *grp, int quota)
{
- struct task_grp *tg = (struct task_grp *)grp;
+ struct task_grp *tg = (struct task_grp *)grp, *tg_root = tg->parent;
+ int old_quota = 0;
int i;
+ if (!tg_root)
+ tg_root = tg;
+
+ if (tg->dont_care) {
+ tg->dont_care = 0;
+ tg_root->total_dont_care_grps--;
+ list_del(&tg->list);
+ } else
+ old_quota = (tg->ticks * 100) / (5 * HZ);
+
+ tg_root->left_over_pct -= (quota - old_quota);
tg->ticks = (quota * 5 * HZ) / 100;
for_each_possible_cpu(i)
tg->rq[i]->ticks = tg->ticks;
+ recalc_dontcare(tg_root);
}
/* Return assigned quota for this group */
@@ -7137,6 +7208,9 @@ int sched_get_quota(void *grp)
struct task_grp *tg = (struct task_grp *)grp;
int quota;
+ if (tg->dont_care)
+ return 0;
+
quota = (tg->ticks * 100) / (5 * HZ);
return quota;
diff -puN include/linux/sched.h~cpu_ctlr_handle_dont_cares include/linux/sched.h
--- linux-2.6.18-rc3/include/linux/sched.h~cpu_ctlr_handle_dont_cares 2006-08-04 08:31:56.000000000 +0530
+++ linux-2.6.18-rc3-root/include/linux/sched.h 2006-08-04 08:32:07.000000000 +0530
@@ -1607,7 +1607,7 @@ static inline int try_to_freeze(void) {
#ifdef CONFIG_CPUMETER
struct task_grp_ops {
- void *(*alloc_group)(void);
+ void *(*alloc_group)(void *grp_parent);
void (*dealloc_group)(void *grp);
void (*assign_quota)(void *grp, int quota);
void (*move_task)(struct task_struct *tsk, void *old, void *new);
_
--
Regards,
vatsa
--
Regards,
vatsa
-
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