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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2010-06-02 14:24:13 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-06-02 14:24:13 +0400 |
| commit | 371121057607e3127e19b3fa094330181b5b031e (patch) | |
| tree | d0803bdf06a50fdad88435588f66b2f0f4c95008 | |
| parent | bc135b23d01acf7ee926aaf75b0020c86d3869f9 (diff) | |
| download | linux-371121057607e3127e19b3fa094330181b5b031e.tar.xz | |
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: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/sch_generic.h | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 9707daed761e..b3591e4a514c 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -23,11 +23,17 @@ struct qdisc_rate_table { }; enum qdisc_state_t { - __QDISC_STATE_RUNNING, __QDISC_STATE_SCHED, __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 list_head list; struct tc_sizespec szopts; @@ -72,23 +78,24 @@ struct Qdisc { unsigned long state; struct sk_buff_head q; struct gnet_stats_basic_packed bstats; + unsigned long __state; struct gnet_stats_queue qstats; struct rcu_head rcu_head; }; 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) { - 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) { - clear_bit(__QDISC_STATE_RUNNING, &qdisc->state); + __clear_bit(__QDISC___STATE_RUNNING, &qdisc->__state); } struct Qdisc_class_ops { |