Commit 2e04ad42 authored by Yang Yingliang's avatar Yang Yingliang Committed by David S. Miller
Browse files

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: default avatarYang Yingliang <yangyingliang@huawei.com>
Acked-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4e2d52bf

include/uapi/linux/pkt_sched.h

+2 −0
Original line number Diff line number Diff line
@@ -173,6 +173,8 @@ enum { 
	TCA_TBF_PTAB,

	TCA_TBF_RATE64,

	TCA_TBF_PRATE64,

	TCA_TBF_BURST,

	TCA_TBF_PBURST,

	__TCA_TBF_MAX,

};

net/sched/sch_tbf.c

+24 −5
Original line number Diff line number Diff line
@@ -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);



	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])
@@ -371,8 +378,14 @@ static int tbf_change(struct Qdisc *sch, struct nlattr *opt) 
			goto done;

		}



		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)))

		pr_warn_ratelimited("sch_tbf: burst %llu is lower than device %s mtu (%u) !\n",
@@ -391,8 +404,14 @@ static int tbf_change(struct Qdisc *sch, struct nlattr *opt) 
		q->qdisc = child;

	}

	q->limit = qopt->limit;

	if (tb[TCA_TBF_PBURST])

		q->mtu = mtu;

	else

		q->mtu = PSCHED_TICKS2NS(qopt->mtu);

	q->max_size = max_size;

	if (tb[TCA_TBF_BURST])

		q->buffer = buffer;

	else

		q->buffer = PSCHED_TICKS2NS(qopt->buffer);

	q->tokens = q->buffer;

	q->ptokens = q->mtu;

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