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net_sched: move TCQ_F_THROTTLED flag

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In commit 3711210576 (net: QDISC_STATE_RUNNING dont need atomic bit
ops) I moved QDISC_STATE_RUNNING flag to __state container, located in
the cache line containing qdisc lock and often dirtied fields.

I now move TCQ_F_THROTTLED bit too, so that we let first cache line read
mostly, and shared by all cpus. This should speedup HTB/CBQ for example.

Not using test_bit()/__clear_bit()/__test_and_set_bit allows to use an
"unsigned int" for __state container, reducing by 8 bytes Qdisc size.

Introduce helpers to hide implementation details.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McHardy <kaber@trash.net>
CC: Jesper Dangaard Brouer <hawk@diku.dk>
CC: Jarek Poplawski <jarkao2@gmail.com>
CC: Jamal Hadi Salim <hadi@cyberus.ca>
CC: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2011-01-20 05:27:16 +00:00 • committed by David S. Miller
commit fd245a4adb
7 changed files with 39 additions and 21 deletions
Download patch file Download diff file Expand all files Collapse all files

38
include/net/sch_generic.h
View file

@ -31,7 +31,8 @@ enum qdisc_state_t {
* following bits are only changed while qdisc lock is held
*/
enum qdisc___state_t {
__QDISC___STATE_RUNNING,
__QDISC___STATE_RUNNING = 1,
__QDISC___STATE_THROTTLED = 2,
};
struct qdisc_size_table {
@ -46,10 +47,9 @@ struct Qdisc {
struct sk_buff * (*dequeue)(struct Qdisc *dev);
unsigned flags;
#define TCQ_F_BUILTIN 1
#define TCQ_F_THROTTLED 2
#define TCQ_F_INGRESS 4
#define TCQ_F_CAN_BYPASS 8
#define TCQ_F_MQROOT 16
#define TCQ_F_INGRESS 2
#define TCQ_F_CAN_BYPASS 4
#define TCQ_F_MQROOT 8
#define TCQ_F_WARN_NONWC (1 << 16)
int padded;
struct Qdisc_ops *ops;
@ -78,25 +78,43 @@ struct Qdisc {
unsigned long state;
struct sk_buff_head q;
struct gnet_stats_basic_packed bstats;
unsigned long __state;
unsigned int __state;
struct gnet_stats_queue qstats;
struct rcu_head rcu_head;
spinlock_t busylock;
};
static inline bool qdisc_is_running(struct Qdisc *qdisc)
static inline bool qdisc_is_running(const struct Qdisc *qdisc)
{
return test_bit(__QDISC___STATE_RUNNING, &qdisc->__state);
return (qdisc->__state & __QDISC___STATE_RUNNING) ? true : false;
}
static inline bool qdisc_run_begin(struct Qdisc *qdisc)
{
return !__test_and_set_bit(__QDISC___STATE_RUNNING, &qdisc->__state);
if (qdisc_is_running(qdisc))
return false;
qdisc->__state |= __QDISC___STATE_RUNNING;
return true;
}
static inline void qdisc_run_end(struct Qdisc *qdisc)
{
__clear_bit(__QDISC___STATE_RUNNING, &qdisc->__state);
qdisc->__state &= ~__QDISC___STATE_RUNNING;
}
static inline bool qdisc_is_throttled(const struct Qdisc *qdisc)
{
return (qdisc->__state & __QDISC___STATE_THROTTLED) ? true : false;
}
static inline void qdisc_throttled(struct Qdisc *qdisc)
{
qdisc->__state |= __QDISC___STATE_THROTTLED;
}
static inline void qdisc_unthrottled(struct Qdisc *qdisc)
{
qdisc->__state &= ~__QDISC___STATE_THROTTLED;
}
struct Qdisc_class_ops {

6
net/sched/sch_api.c
View file

@ -473,7 +473,7 @@ static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
timer);
wd->qdisc->flags &= ~TCQ_F_THROTTLED;
qdisc_unthrottled(wd->qdisc);
__netif_schedule(qdisc_root(wd->qdisc));
return HRTIMER_NORESTART;
@ -495,7 +495,7 @@ void qdisc_watchdog_schedule(struct qdisc_watchdog *wd, psched_time_t expires)
&qdisc_root_sleeping(wd->qdisc)->state))
return;
wd->qdisc->flags |= TCQ_F_THROTTLED;
qdisc_throttled(wd->qdisc);
time = ktime_set(0, 0);
time = ktime_add_ns(time, PSCHED_TICKS2NS(expires));
hrtimer_start(&wd->timer, time, HRTIMER_MODE_ABS);
@ -505,7 +505,7 @@ EXPORT_SYMBOL(qdisc_watchdog_schedule);
void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
{
hrtimer_cancel(&wd->timer);
wd->qdisc->flags &= ~TCQ_F_THROTTLED;
qdisc_unthrottled(wd->qdisc);
}
EXPORT_SYMBOL(qdisc_watchdog_cancel);

6
net/sched/sch_cbq.c
View file

@ -351,7 +351,7 @@ cbq_mark_toplevel(struct cbq_sched_data *q, struct cbq_class *cl)
{
int toplevel = q->toplevel;
if (toplevel > cl->level && !(cl->q->flags & TCQ_F_THROTTLED)) {
if (toplevel > cl->level && !(qdisc_is_throttled(cl->q))) {
psched_time_t now;
psched_tdiff_t incr;
@ -625,7 +625,7 @@ static enum hrtimer_restart cbq_undelay(struct hrtimer *timer)
hrtimer_start(&q->delay_timer, time, HRTIMER_MODE_ABS);
}
sch->flags &= ~TCQ_F_THROTTLED;
qdisc_unthrottled(sch);
__netif_schedule(qdisc_root(sch));
return HRTIMER_NORESTART;
}
@ -974,7 +974,7 @@ cbq_dequeue(struct Qdisc *sch)
skb = cbq_dequeue_1(sch);
if (skb) {
sch->q.qlen--;
sch->flags &= ~TCQ_F_THROTTLED;
qdisc_unthrottled(sch);
return skb;
}

2
net/sched/sch_hfsc.c
View file

@ -1664,7 +1664,7 @@ hfsc_dequeue(struct Qdisc *sch)
set_passive(cl);
}
sch->flags &= ~TCQ_F_THROTTLED;
qdisc_unthrottled(sch);
sch->q.qlen--;
return skb;

4
net/sched/sch_htb.c
View file

@ -865,7 +865,7 @@ static struct sk_buff *htb_dequeue(struct Qdisc *sch)
/* try to dequeue direct packets as high prio (!) to minimize cpu work */
skb = __skb_dequeue(&q->direct_queue);
if (skb != NULL) {
sch->flags &= ~TCQ_F_THROTTLED;
qdisc_unthrottled(sch);
sch->q.qlen--;
return skb;
}
@ -901,7 +901,7 @@ static struct sk_buff *htb_dequeue(struct Qdisc *sch)
skb = htb_dequeue_tree(q, prio, level);
if (likely(skb != NULL)) {
sch->q.qlen--;
sch->flags &= ~TCQ_F_THROTTLED;
qdisc_unthrottled(sch);
goto fin;
}
}

2
net/sched/sch_netem.c
View file

@ -266,7 +266,7 @@ static struct sk_buff *netem_dequeue(struct Qdisc *sch)
struct netem_sched_data *q = qdisc_priv(sch);
struct sk_buff *skb;
if (sch->flags & TCQ_F_THROTTLED)
if (qdisc_is_throttled(sch))
return NULL;
skb = q->qdisc->ops->peek(q->qdisc);

2
net/sched/sch_tbf.c
View file

@ -185,7 +185,7 @@ static struct sk_buff *tbf_dequeue(struct Qdisc *sch)
q->tokens = toks;
q->ptokens = ptoks;
sch->q.qlen--;
sch->flags &= ~TCQ_F_THROTTLED;
qdisc_unthrottled(sch);
return skb;
}