Commit 816219a8 authored by Jakub Kicinski's avatar Jakub Kicinski

Merge branch 'net-sched-fixes-after-recent-qdisc-running-changes'

Eric Dumazet says:

====================
net: sched: fixes after recent qdisc->running changes

First patch fixes a plain bug in qdisc_run_begin().
Second patch removes a pair of atomic operations, increasing performance.
====================

Link: https://lore.kernel.org/r/20211019003402.2110017-1-eric.dumazet@gmail.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 05be9463 97604c65
......@@ -38,10 +38,13 @@ enum qdisc_state_t {
__QDISC_STATE_DEACTIVATED,
__QDISC_STATE_MISSED,
__QDISC_STATE_DRAINING,
};
enum qdisc_state2_t {
/* Only for !TCQ_F_NOLOCK qdisc. Never access it directly.
* Use qdisc_run_begin/end() or qdisc_is_running() instead.
*/
__QDISC_STATE_RUNNING,
__QDISC_STATE2_RUNNING,
};
#define QDISC_STATE_MISSED BIT(__QDISC_STATE_MISSED)
......@@ -114,6 +117,7 @@ struct Qdisc {
struct gnet_stats_basic_sync bstats;
struct gnet_stats_queue qstats;
unsigned long state;
unsigned long state2; /* must be written under qdisc spinlock */
struct Qdisc *next_sched;
struct sk_buff_head skb_bad_txq;
......@@ -154,7 +158,7 @@ static inline bool qdisc_is_running(struct Qdisc *qdisc)
{
if (qdisc->flags & TCQ_F_NOLOCK)
return spin_is_locked(&qdisc->seqlock);
return test_bit(__QDISC_STATE_RUNNING, &qdisc->state);
return test_bit(__QDISC_STATE2_RUNNING, &qdisc->state2);
}
static inline bool nolock_qdisc_is_empty(const struct Qdisc *qdisc)
......@@ -217,7 +221,7 @@ static inline bool qdisc_run_begin(struct Qdisc *qdisc)
*/
return spin_trylock(&qdisc->seqlock);
}
return test_and_set_bit(__QDISC_STATE_RUNNING, &qdisc->state);
return !__test_and_set_bit(__QDISC_STATE2_RUNNING, &qdisc->state2);
}
static inline void qdisc_run_end(struct Qdisc *qdisc)
......@@ -229,7 +233,7 @@ static inline void qdisc_run_end(struct Qdisc *qdisc)
&qdisc->state)))
__netif_schedule(qdisc);
} else {
clear_bit(__QDISC_STATE_RUNNING, &qdisc->state);
__clear_bit(__QDISC_STATE2_RUNNING, &qdisc->state2);
}
}
......
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