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net_sched: remove generic throttled management

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__QDISC_STATE_THROTTLED bit manipulation is rather expensive
for HTB and few others.

I already removed it for sch_fq in commit f2600cf02b
("net: sched: avoid costly atomic operation in fq_dequeue()")
and so far nobody complained.

When one ore more packets are stuck in one or more throttled
HTB class, a htb dequeue() performs two atomic operations
to clear/set __QDISC_STATE_THROTTLED bit, while root qdisc
lock is held.

Removing this pair of atomic operations bring me a 8 % performance
increase on 200 TCP_RR tests, in presence of throttled classes.

This patch has no side effect, since nothing actually uses
disc_is_throttled() anymore.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2016-06-10 16:41:39 -07:00
committed by David S. Miller
parent 42117927ca
commit 45f50bed1d
9 changed files with 6 additions and 35 deletions
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16
include/net/sch_generic.h
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@@ -26,7 +26,6 @@ struct qdisc_rate_table {
enum qdisc_state_t {
__QDISC_STATE_SCHED,
__QDISC_STATE_DEACTIVATED,
__QDISC_STATE_THROTTLED,
};
struct qdisc_size_table {
@@ -125,21 +124,6 @@ static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
#endif
}
static inline bool qdisc_is_throttled(const struct Qdisc *qdisc)
{
return test_bit(__QDISC_STATE_THROTTLED, &qdisc->state) ? true : false;
}
static inline void qdisc_throttled(struct Qdisc *qdisc)
{
set_bit(__QDISC_STATE_THROTTLED, &qdisc->state);
}
static inline void qdisc_unthrottled(struct Qdisc *qdisc)
{
clear_bit(__QDISC_STATE_THROTTLED, &qdisc->state);
}
struct Qdisc_class_ops {
/* Child qdisc manipulation */
struct netdev_queue * (*select_queue)(struct Qdisc *, struct tcmsg *);