Commit 37112105 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller

net: QDISC_STATE_RUNNING dont need atomic bit ops

__QDISC_STATE_RUNNING is always changed while qdisc lock is held.

We can avoid two atomic operations in xmit path, if we move this bit in
a new __state container.

Location of this __state container is carefully chosen so that fast path
only dirties one qdisc cache line.

THROTTLED bit could later be moved into this __state location too, to
avoid dirtying first qdisc cache line.
Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent bc135b23
...@@ -23,11 +23,17 @@ struct qdisc_rate_table { ...@@ -23,11 +23,17 @@ struct qdisc_rate_table {
}; };
enum qdisc_state_t { enum qdisc_state_t {
__QDISC_STATE_RUNNING,
__QDISC_STATE_SCHED, __QDISC_STATE_SCHED,
__QDISC_STATE_DEACTIVATED, __QDISC_STATE_DEACTIVATED,
}; };
/*
* following bits are only changed while qdisc lock is held
*/
enum qdisc___state_t {
__QDISC___STATE_RUNNING,
};
struct qdisc_size_table { struct qdisc_size_table {
struct list_head list; struct list_head list;
struct tc_sizespec szopts; struct tc_sizespec szopts;
...@@ -72,23 +78,24 @@ struct Qdisc { ...@@ -72,23 +78,24 @@ struct Qdisc {
unsigned long state; unsigned long state;
struct sk_buff_head q; struct sk_buff_head q;
struct gnet_stats_basic_packed bstats; struct gnet_stats_basic_packed bstats;
unsigned long __state;
struct gnet_stats_queue qstats; struct gnet_stats_queue qstats;
struct rcu_head rcu_head; struct rcu_head rcu_head;
}; };
static inline bool qdisc_is_running(struct Qdisc *qdisc) static inline bool qdisc_is_running(struct Qdisc *qdisc)
{ {
return test_bit(__QDISC_STATE_RUNNING, &qdisc->state); return test_bit(__QDISC___STATE_RUNNING, &qdisc->__state);
} }
static inline bool qdisc_run_begin(struct Qdisc *qdisc) static inline bool qdisc_run_begin(struct Qdisc *qdisc)
{ {
return !test_and_set_bit(__QDISC_STATE_RUNNING, &qdisc->state); return !__test_and_set_bit(__QDISC___STATE_RUNNING, &qdisc->__state);
} }
static inline void qdisc_run_end(struct Qdisc *qdisc) static inline void qdisc_run_end(struct Qdisc *qdisc)
{ {
clear_bit(__QDISC_STATE_RUNNING, &qdisc->state); __clear_bit(__QDISC___STATE_RUNNING, &qdisc->__state);
} }
struct Qdisc_class_ops { struct Qdisc_class_ops {
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment