diff mbox

[v3,net-next] sch_tbf: add TBF_BURST/TBF_PBURST attribute

Message ID 52B39C5F.1010101@huawei.com
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Yang Yingliang Dec. 20, 2013, 1:24 a.m. UTC 
From: Yang Yingliang <yangyingliang@huawei.com>

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 <yangyingliang@huawei.com>

---
Change note: 

v2 -> v3:
	add parentheses after "else"

v1 -> v2:
	remove an unnecessary tab
---
 include/uapi/linux/pkt_sched.h |  2 ++
 net/sched/sch_tbf.c            | 29 ++++++++++++++++++++++++-----
 2 files changed, 26 insertions(+), 5 deletions(-)

-- 1.8.0

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Comments

Eric Dumazet Dec. 20, 2013, 1:31 a.m. UTC | #1 
On Fri, 2013-12-20 at 09:24 +0800, Yang Yingliang wrote:
> From: Yang Yingliang <yangyingliang@huawei.com>
> 
> 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 <yangyingliang@huawei.com>

Acked-by: Eric Dumazet <edumazet@google.com>

Thanks


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David Miller Dec. 26, 2013, 6:54 p.m. UTC | #2 
From: Yang Yingliang <yangyingliang@huawei.com>
Date: Fri, 20 Dec 2013 09:24:47 +0800

> From: Yang Yingliang <yangyingliang@huawei.com>
> 
> 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 <yangyingliang@huawei.com>

Applied, thanks.
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diff mbox

Patch

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;