diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-04-18 07:32:39 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2024-04-19 11:34:07 +0100 |
| commit | c45bd26c829ea229c067f4096a746ea2f717bc20 (patch) | |
| tree | 4be38801d615b3aedd64ca074af7e027a1edb905 | |
| parent | 7253c1d1e7a52504ffd08138e9843d0a80788690 (diff) | |
| download | next-queue-c45bd26c829ea229c067f4096a746ea2f717bc20.tar.gz | |
net_sched: sch_codel: implement lockless codel_dump()
Instead of relying on RTNL, codel_dump() can use READ_ONCE()
annotations, paired with WRITE_ONCE() ones in codel_change().
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-- | net/sched/sch_codel.c | 29 |
1 files changed, 18 insertions, 11 deletions
diff --git a/net/sched/sch_codel.c b/net/sched/sch_codel.c index ecb3f164bb25b3..3e8d4fe4d91e3e 100644 --- a/net/sched/sch_codel.c +++ b/net/sched/sch_codel.c @@ -118,26 +118,31 @@ static int codel_change(struct Qdisc *sch, struct nlattr *opt, if (tb[TCA_CODEL_TARGET]) { u32 target = nla_get_u32(tb[TCA_CODEL_TARGET]); - q->params.target = ((u64)target * NSEC_PER_USEC) >> CODEL_SHIFT; + WRITE_ONCE(q->params.target, + ((u64)target * NSEC_PER_USEC) >> CODEL_SHIFT); } if (tb[TCA_CODEL_CE_THRESHOLD]) { u64 val = nla_get_u32(tb[TCA_CODEL_CE_THRESHOLD]); - q->params.ce_threshold = (val * NSEC_PER_USEC) >> CODEL_SHIFT; + WRITE_ONCE(q->params.ce_threshold, + (val * NSEC_PER_USEC) >> CODEL_SHIFT); } if (tb[TCA_CODEL_INTERVAL]) { u32 interval = nla_get_u32(tb[TCA_CODEL_INTERVAL]); - q->params.interval = ((u64)interval * NSEC_PER_USEC) >> CODEL_SHIFT; + WRITE_ONCE(q->params.interval, + ((u64)interval * NSEC_PER_USEC) >> CODEL_SHIFT); } if (tb[TCA_CODEL_LIMIT]) - sch->limit = nla_get_u32(tb[TCA_CODEL_LIMIT]); + WRITE_ONCE(sch->limit, + nla_get_u32(tb[TCA_CODEL_LIMIT])); if (tb[TCA_CODEL_ECN]) - q->params.ecn = !!nla_get_u32(tb[TCA_CODEL_ECN]); + WRITE_ONCE(q->params.ecn, + !!nla_get_u32(tb[TCA_CODEL_ECN])); qlen = sch->q.qlen; while (sch->q.qlen > sch->limit) { @@ -183,6 +188,7 @@ static int codel_init(struct Qdisc *sch, struct nlattr *opt, static int codel_dump(struct Qdisc *sch, struct sk_buff *skb) { struct codel_sched_data *q = qdisc_priv(sch); + codel_time_t ce_threshold; struct nlattr *opts; opts = nla_nest_start_noflag(skb, TCA_OPTIONS); @@ -190,17 +196,18 @@ static int codel_dump(struct Qdisc *sch, struct sk_buff *skb) goto nla_put_failure; if (nla_put_u32(skb, TCA_CODEL_TARGET, - codel_time_to_us(q->params.target)) || + codel_time_to_us(READ_ONCE(q->params.target))) || nla_put_u32(skb, TCA_CODEL_LIMIT, - sch->limit) || + READ_ONCE(sch->limit)) || nla_put_u32(skb, TCA_CODEL_INTERVAL, - codel_time_to_us(q->params.interval)) || + codel_time_to_us(READ_ONCE(q->params.interval))) || nla_put_u32(skb, TCA_CODEL_ECN, - q->params.ecn)) + READ_ONCE(q->params.ecn))) goto nla_put_failure; - if (q->params.ce_threshold != CODEL_DISABLED_THRESHOLD && + ce_threshold = READ_ONCE(q->params.ce_threshold); + if (ce_threshold != CODEL_DISABLED_THRESHOLD && nla_put_u32(skb, TCA_CODEL_CE_THRESHOLD, - codel_time_to_us(q->params.ce_threshold))) + codel_time_to_us(ce_threshold))) goto nla_put_failure; return nla_nest_end(skb, opts); |