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| author | Eric Dumazet <edumazet@google.com> | 2024-04-18 07:32:38 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2024-04-19 11:34:07 +0100 |
| commit | 7253c1d1e7a52504ffd08138e9843d0a80788690 (patch) | |
| tree | 60d373481145b86da0fc8b8fdc9728cd7f9afda3 | |
| parent | 8eb54a421a625a7797549d7bdad3f6c70c49180c (diff) | |
| download | gtp-7253c1d1e7a52504ffd08138e9843d0a80788690.tar.gz | |
net_sched: sch_choke: implement lockless choke_dump()
Instead of relying on RTNL, choke_dump() can use READ_ONCE()
annotations, paired with WRITE_ONCE() ones in choke_change().
v2: added a WRITE_ONCE(p->Scell_log, Scell_log)
per Simon feedback in V1
Removed the READ_ONCE(q->limit) in choke_enqueue()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/red.h | 12 | ||||
| -rw-r--r-- | net/sched/sch_choke.c | 21 |
2 files changed, 17 insertions, 16 deletions
diff --git a/include/net/red.h b/include/net/red.h index 425364de0df791..802287d52c9e37 100644 --- a/include/net/red.h +++ b/include/net/red.h @@ -233,10 +233,10 @@ static inline void red_set_parms(struct red_parms *p, int delta = qth_max - qth_min; u32 max_p_delta; - p->qth_min = qth_min << Wlog; - p->qth_max = qth_max << Wlog; - p->Wlog = Wlog; - p->Plog = Plog; + WRITE_ONCE(p->qth_min, qth_min << Wlog); + WRITE_ONCE(p->qth_max, qth_max << Wlog); + WRITE_ONCE(p->Wlog, Wlog); + WRITE_ONCE(p->Plog, Plog); if (delta <= 0) delta = 1; p->qth_delta = delta; @@ -244,7 +244,7 @@ static inline void red_set_parms(struct red_parms *p, max_P = red_maxp(Plog); max_P *= delta; /* max_P = (qth_max - qth_min)/2^Plog */ } - p->max_P = max_P; + WRITE_ONCE(p->max_P, max_P); max_p_delta = max_P / delta; max_p_delta = max(max_p_delta, 1U); p->max_P_reciprocal = reciprocal_value(max_p_delta); @@ -257,7 +257,7 @@ static inline void red_set_parms(struct red_parms *p, p->target_min = qth_min + 2*delta; p->target_max = qth_min + 3*delta; - p->Scell_log = Scell_log; + WRITE_ONCE(p->Scell_log, Scell_log); p->Scell_max = (255 << Scell_log); if (stab) diff --git a/net/sched/sch_choke.c b/net/sched/sch_choke.c index ea108030c6b410..91072010923d18 100644 --- a/net/sched/sch_choke.c +++ b/net/sched/sch_choke.c @@ -405,8 +405,8 @@ static int choke_change(struct Qdisc *sch, struct nlattr *opt, } else sch_tree_lock(sch); - q->flags = ctl->flags; - q->limit = ctl->limit; + WRITE_ONCE(q->flags, ctl->flags); + WRITE_ONCE(q->limit, ctl->limit); red_set_parms(&q->parms, ctl->qth_min, ctl->qth_max, ctl->Wlog, ctl->Plog, ctl->Scell_log, @@ -431,15 +431,16 @@ static int choke_init(struct Qdisc *sch, struct nlattr *opt, static int choke_dump(struct Qdisc *sch, struct sk_buff *skb) { struct choke_sched_data *q = qdisc_priv(sch); + u8 Wlog = READ_ONCE(q->parms.Wlog); struct nlattr *opts = NULL; struct tc_red_qopt opt = { - .limit = q->limit, - .flags = q->flags, - .qth_min = q->parms.qth_min >> q->parms.Wlog, - .qth_max = q->parms.qth_max >> q->parms.Wlog, - .Wlog = q->parms.Wlog, - .Plog = q->parms.Plog, - .Scell_log = q->parms.Scell_log, + .limit = READ_ONCE(q->limit), + .flags = READ_ONCE(q->flags), + .qth_min = READ_ONCE(q->parms.qth_min) >> Wlog, + .qth_max = READ_ONCE(q->parms.qth_max) >> Wlog, + .Wlog = Wlog, + .Plog = READ_ONCE(q->parms.Plog), + .Scell_log = READ_ONCE(q->parms.Scell_log), }; opts = nla_nest_start_noflag(skb, TCA_OPTIONS); @@ -447,7 +448,7 @@ static int choke_dump(struct Qdisc *sch, struct sk_buff *skb) goto nla_put_failure; if (nla_put(skb, TCA_CHOKE_PARMS, sizeof(opt), &opt) || - nla_put_u32(skb, TCA_CHOKE_MAX_P, q->parms.max_P)) + nla_put_u32(skb, TCA_CHOKE_MAX_P, READ_ONCE(q->parms.max_P))) goto nla_put_failure; return nla_nest_end(skb, opts); |