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yaml
---
r: 340640
b: refs/heads/master
c: 56b765b
h: refs/heads/master
v: v3
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Vimalkumar authored and David S. Miller committed Nov 3, 2012
1 parent 7ed4986 commit 3f184ba
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Showing 2 changed files with 91 additions and 39 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: afb97186f5d8f1d552298e7423e84c4282e48b92
refs/heads/master: 56b765b79e9a78dc7d3f8850ba5e5567205a3ecd
128 changes: 90 additions & 38 deletions trunk/net/sched/sch_htb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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 */
};

Expand Down Expand Up @@ -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)
{
Expand Down Expand Up @@ -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;

Expand Down Expand Up @@ -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;
Expand All @@ -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;
Expand All @@ -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);

Expand Down Expand Up @@ -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;

Expand All @@ -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++;
Expand Down Expand Up @@ -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)
Expand All @@ -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);
Expand Down Expand Up @@ -834,7 +879,6 @@ static struct sk_buff *htb_dequeue_tree(struct htb_sched *q, int prio,
} 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;
Expand Down Expand Up @@ -871,10 +915,10 @@ static struct sk_buff *htb_dequeue(struct Qdisc *sch)

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 */
Expand All @@ -884,7 +928,7 @@ static struct sk_buff *htb_dequeue(struct Qdisc *sch)
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];
Expand All @@ -903,10 +947,17 @@ static struct sk_buff *htb_dequeue(struct Qdisc *sch)
}
}
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;
}
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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);
}
Expand Down Expand Up @@ -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);
Expand Down

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