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-rw-r--r--net/sched/sch_htb.c128
1 files changed, 90 insertions, 38 deletions
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 9d75b77..32a8097 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -71,6 +71,12 @@ enum htb_cmode {
HTB_CAN_SEND /* class can send */
};
+struct htb_rate_cfg {
+ u64 rate_bps;
+ u32 mult;
+ u32 shift;
+};
+
/* interior & leaf nodes; props specific to leaves are marked L: */
struct htb_class {
struct Qdisc_class_common common;
@@ -118,11 +124,11 @@ struct htb_class {
int filter_cnt;
/* token bucket parameters */
- struct qdisc_rate_table *rate; /* rate table of the class itself */
- struct qdisc_rate_table *ceil; /* ceiling rate (limits borrows too) */
- long buffer, cbuffer; /* token bucket depth/rate */
+ struct htb_rate_cfg rate;
+ struct htb_rate_cfg ceil;
+ s64 buffer, cbuffer; /* token bucket depth/rate */
psched_tdiff_t mbuffer; /* max wait time */
- long tokens, ctokens; /* current number of tokens */
+ s64 tokens, ctokens; /* current number of tokens */
psched_time_t t_c; /* checkpoint time */
};
@@ -162,6 +168,45 @@ struct htb_sched {
struct work_struct work;
};
+static u64 l2t_ns(struct htb_rate_cfg *r, unsigned int len)
+{
+ return ((u64)len * r->mult) >> r->shift;
+}
+
+static void htb_precompute_ratedata(struct htb_rate_cfg *r)
+{
+ u64 factor;
+ u64 mult;
+ int shift;
+
+ r->shift = 0;
+ r->mult = 1;
+ /*
+ * Calibrate mult, shift so that token counting is accurate
+ * for smallest packet size (64 bytes). Token (time in ns) is
+ * computed as (bytes * 8) * NSEC_PER_SEC / rate_bps. It will
+ * work as long as the smallest packet transfer time can be
+ * accurately represented in nanosec.
+ */
+ if (r->rate_bps > 0) {
+ /*
+ * Higher shift gives better accuracy. Find the largest
+ * shift such that mult fits in 32 bits.
+ */
+ for (shift = 0; shift < 16; shift++) {
+ r->shift = shift;
+ factor = 8LLU * NSEC_PER_SEC * (1 << r->shift);
+ mult = div64_u64(factor, r->rate_bps);
+ if (mult > UINT_MAX)
+ break;
+ }
+
+ r->shift = shift - 1;
+ factor = 8LLU * NSEC_PER_SEC * (1 << r->shift);
+ r->mult = div64_u64(factor, r->rate_bps);
+ }
+}
+
/* find class in global hash table using given handle */
static inline struct htb_class *htb_find(u32 handle, struct Qdisc *sch)
{
@@ -273,7 +318,7 @@ static void htb_add_to_id_tree(struct rb_root *root,
* already in the queue.
*/
static void htb_add_to_wait_tree(struct htb_sched *q,
- struct htb_class *cl, long delay)
+ struct htb_class *cl, s64 delay)
{
struct rb_node **p = &q->wait_pq[cl->level].rb_node, *parent = NULL;
@@ -441,14 +486,14 @@ static void htb_deactivate_prios(struct htb_sched *q, struct htb_class *cl)
htb_remove_class_from_row(q, cl, mask);
}
-static inline long htb_lowater(const struct htb_class *cl)
+static inline s64 htb_lowater(const struct htb_class *cl)
{
if (htb_hysteresis)
return cl->cmode != HTB_CANT_SEND ? -cl->cbuffer : 0;
else
return 0;
}
-static inline long htb_hiwater(const struct htb_class *cl)
+static inline s64 htb_hiwater(const struct htb_class *cl)
{
if (htb_hysteresis)
return cl->cmode == HTB_CAN_SEND ? -cl->buffer : 0;
@@ -469,9 +514,9 @@ static inline long htb_hiwater(const struct htb_class *cl)
* mode transitions per time unit. The speed gain is about 1/6.
*/
static inline enum htb_cmode
-htb_class_mode(struct htb_class *cl, long *diff)
+htb_class_mode(struct htb_class *cl, s64 *diff)
{
- long toks;
+ s64 toks;
if ((toks = (cl->ctokens + *diff)) < htb_lowater(cl)) {
*diff = -toks;
@@ -495,7 +540,7 @@ htb_class_mode(struct htb_class *cl, long *diff)
* to mode other than HTB_CAN_SEND (see htb_add_to_wait_tree).
*/
static void
-htb_change_class_mode(struct htb_sched *q, struct htb_class *cl, long *diff)
+htb_change_class_mode(struct htb_sched *q, struct htb_class *cl, s64 *diff)
{
enum htb_cmode new_mode = htb_class_mode(cl, diff);
@@ -581,26 +626,26 @@ static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch)
return NET_XMIT_SUCCESS;
}
-static inline void htb_accnt_tokens(struct htb_class *cl, int bytes, long diff)
+static inline void htb_accnt_tokens(struct htb_class *cl, int bytes, s64 diff)
{
- long toks = diff + cl->tokens;
+ s64 toks = diff + cl->tokens;
if (toks > cl->buffer)
toks = cl->buffer;
- toks -= (long) qdisc_l2t(cl->rate, bytes);
+ toks -= (s64) l2t_ns(&cl->rate, bytes);
if (toks <= -cl->mbuffer)
toks = 1 - cl->mbuffer;
cl->tokens = toks;
}
-static inline void htb_accnt_ctokens(struct htb_class *cl, int bytes, long diff)
+static inline void htb_accnt_ctokens(struct htb_class *cl, int bytes, s64 diff)
{
- long toks = diff + cl->ctokens;
+ s64 toks = diff + cl->ctokens;
if (toks > cl->cbuffer)
toks = cl->cbuffer;
- toks -= (long) qdisc_l2t(cl->ceil, bytes);
+ toks -= (s64) l2t_ns(&cl->ceil, bytes);
if (toks <= -cl->mbuffer)
toks = 1 - cl->mbuffer;
@@ -623,10 +668,10 @@ static void htb_charge_class(struct htb_sched *q, struct htb_class *cl,
{
int bytes = qdisc_pkt_len(skb);
enum htb_cmode old_mode;
- long diff;
+ s64 diff;
while (cl) {
- diff = psched_tdiff_bounded(q->now, cl->t_c, cl->mbuffer);
+ diff = min_t(s64, q->now - cl->t_c, cl->mbuffer);
if (cl->level >= level) {
if (cl->level == level)
cl->xstats.lends++;
@@ -673,7 +718,7 @@ static psched_time_t htb_do_events(struct htb_sched *q, int level,
unsigned long stop_at = start + 2;
while (time_before(jiffies, stop_at)) {
struct htb_class *cl;
- long diff;
+ s64 diff;
struct rb_node *p = rb_first(&q->wait_pq[level]);
if (!p)
@@ -684,7 +729,7 @@ static psched_time_t htb_do_events(struct htb_sched *q, int level,
return cl->pq_key;
htb_safe_rb_erase(p, q->wait_pq + level);
- diff = psched_tdiff_bounded(q->now, cl->t_c, cl->mbuffer);
+ diff = min_t(s64, q->now - cl->t_c, cl->mbuffer);
htb_change_class_mode(q, cl, &diff);
if (cl->cmode != HTB_CAN_SEND)
htb_add_to_wait_tree(q, cl, diff);
@@ -834,7 +879,6 @@ next:
} while (cl != start);
if (likely(skb != NULL)) {
- bstats_update(&cl->bstats, skb);
cl->un.leaf.deficit[level] -= qdisc_pkt_len(skb);
if (cl->un.leaf.deficit[level] < 0) {
cl->un.leaf.deficit[level] += cl->quantum;
@@ -871,10 +915,10 @@ ok:
if (!sch->q.qlen)
goto fin;
- q->now = psched_get_time();
+ q->now = ktime_to_ns(ktime_get());
start_at = jiffies;
- next_event = q->now + 5 * PSCHED_TICKS_PER_SEC;
+ next_event = q->now + 5 * NSEC_PER_SEC;
for (level = 0; level < TC_HTB_MAXDEPTH; level++) {
/* common case optimization - skip event handler quickly */
@@ -884,7 +928,7 @@ ok:
if (q->now >= q->near_ev_cache[level]) {
event = htb_do_events(q, level, start_at);
if (!event)
- event = q->now + PSCHED_TICKS_PER_SEC;
+ event = q->now + NSEC_PER_SEC;
q->near_ev_cache[level] = event;
} else
event = q->near_ev_cache[level];
@@ -903,10 +947,17 @@ ok:
}
}
sch->qstats.overlimits++;
- if (likely(next_event > q->now))
- qdisc_watchdog_schedule(&q->watchdog, next_event);
- else
+ if (likely(next_event > q->now)) {
+ if (!test_bit(__QDISC_STATE_DEACTIVATED,
+ &qdisc_root_sleeping(q->watchdog.qdisc)->state)) {
+ ktime_t time = ns_to_ktime(next_event);
+ qdisc_throttled(q->watchdog.qdisc);
+ hrtimer_start(&q->watchdog.timer, time,
+ HRTIMER_MODE_ABS);
+ }
+ } else {
schedule_work(&q->work);
+ }
fin:
return skb;
}
@@ -1082,9 +1133,9 @@ static int htb_dump_class(struct Qdisc *sch, unsigned long arg,
memset(&opt, 0, sizeof(opt));
- opt.rate = cl->rate->rate;
+ opt.rate.rate = cl->rate.rate_bps >> 3;
opt.buffer = cl->buffer;
- opt.ceil = cl->ceil->rate;
+ opt.ceil.rate = cl->ceil.rate_bps >> 3;
opt.cbuffer = cl->cbuffer;
opt.quantum = cl->quantum;
opt.prio = cl->prio;
@@ -1203,9 +1254,6 @@ static void htb_destroy_class(struct Qdisc *sch, struct htb_class *cl)
qdisc_destroy(cl->un.leaf.q);
}
gen_kill_estimator(&cl->bstats, &cl->rate_est);
- qdisc_put_rtab(cl->rate);
- qdisc_put_rtab(cl->ceil);
-
tcf_destroy_chain(&cl->filter_list);
kfree(cl);
}
@@ -1460,12 +1508,16 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
cl->buffer = hopt->buffer;
cl->cbuffer = hopt->cbuffer;
- if (cl->rate)
- qdisc_put_rtab(cl->rate);
- cl->rate = rtab;
- if (cl->ceil)
- qdisc_put_rtab(cl->ceil);
- cl->ceil = ctab;
+
+ cl->rate.rate_bps = (u64)rtab->rate.rate << 3;
+ cl->ceil.rate_bps = (u64)ctab->rate.rate << 3;
+
+ htb_precompute_ratedata(&cl->rate);
+ htb_precompute_ratedata(&cl->ceil);
+
+ cl->buffer = hopt->buffer << PSCHED_SHIFT;
+ cl->cbuffer = hopt->buffer << PSCHED_SHIFT;
+
sch_tree_unlock(sch);
qdisc_class_hash_grow(sch, &q->clhash);
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