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| author | Eric Dumazet <edumazet@google.com> | 2024-04-18 07:32:47 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2024-04-19 11:34:08 +0100 |
| commit | 6c00dc4fdb40fa434cb1271fac3a1201449cb4d3 (patch) | |
| tree | 7f0a98105eac4c3f39f7774deab52d2aafd8dbdb | |
| parent | 293c7e2b3e2fb7796778e3e61d94d58546fe96eb (diff) | |
| download | next-queue-6c00dc4fdb40fa434cb1271fac3a1201449cb4d3.tar.gz | |
net_sched: sch_pie: implement lockless pie_dump()
Instead of relying on RTNL, pie_dump() can use READ_ONCE()
annotations, paired with WRITE_ONCE() ones in pie_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_pie.c | 39 |
1 files changed, 21 insertions, 18 deletions
diff --git a/net/sched/sch_pie.c b/net/sched/sch_pie.c index 1764059b063536..b3dcb845b32759 100644 --- a/net/sched/sch_pie.c +++ b/net/sched/sch_pie.c @@ -156,36 +156,38 @@ static int pie_change(struct Qdisc *sch, struct nlattr *opt, u32 target = nla_get_u32(tb[TCA_PIE_TARGET]); /* convert to pschedtime */ - q->params.target = PSCHED_NS2TICKS((u64)target * NSEC_PER_USEC); + WRITE_ONCE(q->params.target, + PSCHED_NS2TICKS((u64)target * NSEC_PER_USEC)); } /* tupdate is in jiffies */ if (tb[TCA_PIE_TUPDATE]) - q->params.tupdate = - usecs_to_jiffies(nla_get_u32(tb[TCA_PIE_TUPDATE])); + WRITE_ONCE(q->params.tupdate, + usecs_to_jiffies(nla_get_u32(tb[TCA_PIE_TUPDATE]))); if (tb[TCA_PIE_LIMIT]) { u32 limit = nla_get_u32(tb[TCA_PIE_LIMIT]); - q->params.limit = limit; - sch->limit = limit; + WRITE_ONCE(q->params.limit, limit); + WRITE_ONCE(sch->limit, limit); } if (tb[TCA_PIE_ALPHA]) - q->params.alpha = nla_get_u32(tb[TCA_PIE_ALPHA]); + WRITE_ONCE(q->params.alpha, nla_get_u32(tb[TCA_PIE_ALPHA])); if (tb[TCA_PIE_BETA]) - q->params.beta = nla_get_u32(tb[TCA_PIE_BETA]); + WRITE_ONCE(q->params.beta, nla_get_u32(tb[TCA_PIE_BETA])); if (tb[TCA_PIE_ECN]) - q->params.ecn = nla_get_u32(tb[TCA_PIE_ECN]); + WRITE_ONCE(q->params.ecn, nla_get_u32(tb[TCA_PIE_ECN])); if (tb[TCA_PIE_BYTEMODE]) - q->params.bytemode = nla_get_u32(tb[TCA_PIE_BYTEMODE]); + WRITE_ONCE(q->params.bytemode, + nla_get_u32(tb[TCA_PIE_BYTEMODE])); if (tb[TCA_PIE_DQ_RATE_ESTIMATOR]) - q->params.dq_rate_estimator = - nla_get_u32(tb[TCA_PIE_DQ_RATE_ESTIMATOR]); + WRITE_ONCE(q->params.dq_rate_estimator, + nla_get_u32(tb[TCA_PIE_DQ_RATE_ESTIMATOR])); /* Drop excess packets if new limit is lower */ qlen = sch->q.qlen; @@ -469,17 +471,18 @@ static int pie_dump(struct Qdisc *sch, struct sk_buff *skb) /* convert target from pschedtime to us */ if (nla_put_u32(skb, TCA_PIE_TARGET, - ((u32)PSCHED_TICKS2NS(q->params.target)) / + ((u32)PSCHED_TICKS2NS(READ_ONCE(q->params.target))) / NSEC_PER_USEC) || - nla_put_u32(skb, TCA_PIE_LIMIT, sch->limit) || + nla_put_u32(skb, TCA_PIE_LIMIT, READ_ONCE(sch->limit)) || nla_put_u32(skb, TCA_PIE_TUPDATE, - jiffies_to_usecs(q->params.tupdate)) || - nla_put_u32(skb, TCA_PIE_ALPHA, q->params.alpha) || - nla_put_u32(skb, TCA_PIE_BETA, q->params.beta) || + jiffies_to_usecs(READ_ONCE(q->params.tupdate))) || + nla_put_u32(skb, TCA_PIE_ALPHA, READ_ONCE(q->params.alpha)) || + nla_put_u32(skb, TCA_PIE_BETA, READ_ONCE(q->params.beta)) || nla_put_u32(skb, TCA_PIE_ECN, q->params.ecn) || - nla_put_u32(skb, TCA_PIE_BYTEMODE, q->params.bytemode) || + nla_put_u32(skb, TCA_PIE_BYTEMODE, + READ_ONCE(q->params.bytemode)) || nla_put_u32(skb, TCA_PIE_DQ_RATE_ESTIMATOR, - q->params.dq_rate_estimator)) + READ_ONCE(q->params.dq_rate_estimator))) goto nla_put_failure; return nla_nest_end(skb, opts); |