From 160d5e10f87b1dc88fd9b84b31b1718e0fd76398 Mon Sep 17 00:00:00 2001 From: Jarek Poplawski Date: Fri, 8 Dec 2006 00:26:56 -0800 Subject: [PATCH] [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 Signed-off-by: David S. Miller --- net/sched/sch_htb.c | 51 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index 215e68c2b6..15f23c5511 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -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; -- 2.39.5