From 2e04ad424b03661ec8239acd52146497eb33be1c Mon Sep 17 00:00:00 2001 From: Yang Yingliang Date: Fri, 20 Dec 2013 09:24:47 +0800 Subject: [PATCH] sch_tbf: add TBF_BURST/TBF_PBURST attribute When we set burst to 1514 with low rate in userspace, the kernel get a value of burst that less than 1514, which doesn't work. Because it may make some loss when transform burst to buffer in userspace. This makes burst lose some bytes, when the kernel transform the buffer back to burst. This patch adds two new attributes to support sending burst/mtu to kernel directly to avoid the loss. Signed-off-by: Yang Yingliang Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- include/uapi/linux/pkt_sched.h | 2 ++ net/sched/sch_tbf.c | 29 ++++++++++++++++++++++++----- 2 files changed, 26 insertions(+), 5 deletions(-) diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h index 4566993..fe11920 100644 --- a/include/uapi/linux/pkt_sched.h +++ b/include/uapi/linux/pkt_sched.h @@ -173,6 +173,8 @@ enum { TCA_TBF_PTAB, TCA_TBF_RATE64, TCA_TBF_PRATE64, + TCA_TBF_BURST, + TCA_TBF_PBURST, __TCA_TBF_MAX, }; diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c index 887e672..fbba5b0 100644 --- a/net/sched/sch_tbf.c +++ b/net/sched/sch_tbf.c @@ -307,6 +307,8 @@ static const struct nla_policy tbf_policy[TCA_TBF_MAX + 1] = { [TCA_TBF_PTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE }, [TCA_TBF_RATE64] = { .type = NLA_U64 }, [TCA_TBF_PRATE64] = { .type = NLA_U64 }, + [TCA_TBF_BURST] = { .type = NLA_U32 }, + [TCA_TBF_PBURST] = { .type = NLA_U32 }, }; static int tbf_change(struct Qdisc *sch, struct nlattr *opt) @@ -358,7 +360,12 @@ static int tbf_change(struct Qdisc *sch, struct nlattr *opt) rate64 = nla_get_u64(tb[TCA_TBF_RATE64]); psched_ratecfg_precompute(&rate, &qopt->rate, rate64); - max_size = min_t(u64, psched_ns_t2l(&rate, buffer), ~0U); + if (tb[TCA_TBF_BURST]) { + max_size = nla_get_u32(tb[TCA_TBF_BURST]); + buffer = psched_l2t_ns(&rate, max_size); + } else { + max_size = min_t(u64, psched_ns_t2l(&rate, buffer), ~0U); + } if (qopt->peakrate.rate) { if (tb[TCA_TBF_PRATE64]) @@ -366,12 +373,18 @@ static int tbf_change(struct Qdisc *sch, struct nlattr *opt) psched_ratecfg_precompute(&peak, &qopt->peakrate, prate64); if (peak.rate_bytes_ps <= rate.rate_bytes_ps) { pr_warn_ratelimited("sch_tbf: peakrate %llu is lower than or equals to rate %llu !\n", - peak.rate_bytes_ps, rate.rate_bytes_ps); + peak.rate_bytes_ps, rate.rate_bytes_ps); err = -EINVAL; goto done; } - max_size = min_t(u64, max_size, psched_ns_t2l(&peak, mtu)); + if (tb[TCA_TBF_PBURST]) { + u32 pburst = nla_get_u32(tb[TCA_TBF_PBURST]); + max_size = min_t(u32, max_size, pburst); + mtu = psched_l2t_ns(&peak, pburst); + } else { + max_size = min_t(u64, max_size, psched_ns_t2l(&peak, mtu)); + } } if (max_size < psched_mtu(qdisc_dev(sch))) @@ -391,9 +404,15 @@ static int tbf_change(struct Qdisc *sch, struct nlattr *opt) q->qdisc = child; } q->limit = qopt->limit; - q->mtu = PSCHED_TICKS2NS(qopt->mtu); + if (tb[TCA_TBF_PBURST]) + q->mtu = mtu; + else + q->mtu = PSCHED_TICKS2NS(qopt->mtu); q->max_size = max_size; - q->buffer = PSCHED_TICKS2NS(qopt->buffer); + if (tb[TCA_TBF_BURST]) + q->buffer = buffer; + else + q->buffer = PSCHED_TICKS2NS(qopt->buffer); q->tokens = q->buffer; q->ptokens = q->mtu; -- 2.7.4