[NET_SCHED] sch_htb: turn intermediate classes into leaves

- turn intermediate classes into leaves again when their
  last child is deleted (struct htb_class changed)

Signed-off-by: Jarek Poplawski <jarkao2@o2.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jarek Poplawski 2006-12-08 00:26:56 -08:00 committed by David S. Miller
parent a37ef2e325
commit 160d5e10f8

View file

@ -147,6 +147,10 @@ struct htb_class {
psched_tdiff_t mbuffer; /* max wait time */
long tokens, ctokens; /* current number of tokens */
psched_time_t t_c; /* checkpoint time */
int prio; /* For parent to leaf return possible here */
int quantum; /* we do backup. Finally full replacement */
/* of un.leaf originals should be done. */
};
/* TODO: maybe compute rate when size is too large .. or drop ? */
@ -1271,6 +1275,38 @@ static void htb_destroy_filters(struct tcf_proto **fl)
}
}
static inline int htb_parent_last_child(struct htb_class *cl)
{
if (!cl->parent)
/* the root class */
return 0;
if (!(cl->parent->children.next == &cl->sibling &&
cl->parent->children.prev == &cl->sibling))
/* not the last child */
return 0;
return 1;
}
static void htb_parent_to_leaf(struct htb_class *cl, struct Qdisc *new_q)
{
struct htb_class *parent = cl->parent;
BUG_TRAP(!cl->level && cl->un.leaf.q && !cl->prio_activity);
parent->level = 0;
memset(&parent->un.inner, 0, sizeof(parent->un.inner));
INIT_LIST_HEAD(&parent->un.leaf.drop_list);
parent->un.leaf.q = new_q ? new_q : &noop_qdisc;
parent->un.leaf.quantum = parent->quantum;
parent->un.leaf.prio = parent->prio;
parent->tokens = parent->buffer;
parent->ctokens = parent->cbuffer;
PSCHED_GET_TIME(parent->t_c);
parent->cmode = HTB_CAN_SEND;
}
static void htb_destroy_class(struct Qdisc *sch, struct htb_class *cl)
{
struct htb_sched *q = qdisc_priv(sch);
@ -1328,6 +1364,8 @@ static int htb_delete(struct Qdisc *sch, unsigned long arg)
struct htb_sched *q = qdisc_priv(sch);
struct htb_class *cl = (struct htb_class *)arg;
unsigned int qlen;
struct Qdisc *new_q = NULL;
int last_child = 0;
// TODO: why don't allow to delete subtree ? references ? does
// tc subsys quarantee us that in htb_destroy it holds no class
@ -1335,6 +1373,12 @@ static int htb_delete(struct Qdisc *sch, unsigned long arg)
if (!list_empty(&cl->children) || cl->filter_cnt)
return -EBUSY;
if (!cl->level && htb_parent_last_child(cl)) {
new_q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops,
cl->parent->classid);
last_child = 1;
}
sch_tree_lock(sch);
/* delete from hash and active; remainder in destroy_class */
@ -1349,6 +1393,9 @@ static int htb_delete(struct Qdisc *sch, unsigned long arg)
if (cl->prio_activity)
htb_deactivate(q, cl);
if (last_child)
htb_parent_to_leaf(cl, new_q);
if (--cl->refcnt == 0)
htb_destroy_class(sch, cl);
@ -1483,6 +1530,10 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
cl->un.leaf.quantum = hopt->quantum;
if ((cl->un.leaf.prio = hopt->prio) >= TC_HTB_NUMPRIO)
cl->un.leaf.prio = TC_HTB_NUMPRIO - 1;
/* backup for htb_parent_to_leaf */
cl->quantum = cl->un.leaf.quantum;
cl->prio = cl->un.leaf.prio;
}
cl->buffer = hopt->buffer;