133 lines
4.5 KiB
Diff
133 lines
4.5 KiB
Diff
From 7bd90773f89001ea4960ed47676b550137f3facb Mon Sep 17 00:00:00 2001
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From: Eric Dumazet <edumazet@google.com>
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Date: Wed, 16 May 2012 04:39:09 +0000
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Subject: [PATCH] fq_codel: should use qdisc backlog as threshold
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commit 865ec5523dadbedefbc5710a68969f686a28d928 upstream.
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codel_should_drop() logic allows a packet being not dropped if queue
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size is under max packet size.
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In fq_codel, we have two possible backlogs : The qdisc global one, and
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the flow local one.
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The meaningful one for codel_should_drop() should be the global backlog,
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not the per flow one, so that thin flows can have a non zero drop/mark
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probability.
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Signed-off-by: Eric Dumazet <edumazet@google.com>
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Cc: Dave Taht <dave.taht@bufferbloat.net>
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Cc: Kathleen Nichols <nichols@pollere.com>
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Cc: Van Jacobson <van@pollere.net>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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---
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include/net/codel.h | 15 +++++++--------
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net/sched/sch_codel.c | 4 ++--
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net/sched/sch_fq_codel.c | 5 +++--
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3 files changed, 12 insertions(+), 12 deletions(-)
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--- a/include/net/codel.h
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+++ b/include/net/codel.h
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@@ -205,7 +205,7 @@ static codel_time_t codel_control_law(co
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static bool codel_should_drop(const struct sk_buff *skb,
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- unsigned int *backlog,
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+ struct Qdisc *sch,
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struct codel_vars *vars,
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struct codel_params *params,
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struct codel_stats *stats,
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@@ -219,13 +219,13 @@ static bool codel_should_drop(const stru
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}
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vars->ldelay = now - codel_get_enqueue_time(skb);
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- *backlog -= qdisc_pkt_len(skb);
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+ sch->qstats.backlog -= qdisc_pkt_len(skb);
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if (unlikely(qdisc_pkt_len(skb) > stats->maxpacket))
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stats->maxpacket = qdisc_pkt_len(skb);
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if (codel_time_before(vars->ldelay, params->target) ||
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- *backlog <= stats->maxpacket) {
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+ sch->qstats.backlog <= stats->maxpacket) {
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/* went below - stay below for at least interval */
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vars->first_above_time = 0;
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return false;
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@@ -249,8 +249,7 @@ static struct sk_buff *codel_dequeue(str
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struct codel_params *params,
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struct codel_vars *vars,
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struct codel_stats *stats,
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- codel_skb_dequeue_t dequeue_func,
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- u32 *backlog)
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+ codel_skb_dequeue_t dequeue_func)
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{
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struct sk_buff *skb = dequeue_func(vars, sch);
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codel_time_t now;
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@@ -261,7 +260,7 @@ static struct sk_buff *codel_dequeue(str
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return skb;
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}
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now = codel_get_time();
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- drop = codel_should_drop(skb, backlog, vars, params, stats, now);
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+ drop = codel_should_drop(skb, sch, vars, params, stats, now);
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if (vars->dropping) {
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if (!drop) {
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/* sojourn time below target - leave dropping state */
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@@ -292,7 +291,7 @@ static struct sk_buff *codel_dequeue(str
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qdisc_drop(skb, sch);
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stats->drop_count++;
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skb = dequeue_func(vars, sch);
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- if (!codel_should_drop(skb, backlog,
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+ if (!codel_should_drop(skb, sch,
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vars, params, stats, now)) {
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/* leave dropping state */
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vars->dropping = false;
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@@ -313,7 +312,7 @@ static struct sk_buff *codel_dequeue(str
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stats->drop_count++;
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skb = dequeue_func(vars, sch);
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- drop = codel_should_drop(skb, backlog, vars, params,
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+ drop = codel_should_drop(skb, sch, vars, params,
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stats, now);
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}
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vars->dropping = true;
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--- a/net/sched/sch_codel.c
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+++ b/net/sched/sch_codel.c
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@@ -77,8 +77,8 @@ static struct sk_buff *codel_qdisc_deque
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struct codel_sched_data *q = qdisc_priv(sch);
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struct sk_buff *skb;
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- skb = codel_dequeue(sch, &q->params, &q->vars, &q->stats,
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- dequeue, &sch->qstats.backlog);
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+ skb = codel_dequeue(sch, &q->params, &q->vars, &q->stats, dequeue);
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+
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/* We cant call qdisc_tree_decrease_qlen() if our qlen is 0,
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* or HTB crashes. Defer it for next round.
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*/
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--- a/net/sched/sch_fq_codel.c
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+++ b/net/sched/sch_fq_codel.c
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@@ -217,13 +217,14 @@ static int fq_codel_enqueue(struct sk_bu
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*/
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static struct sk_buff *dequeue(struct codel_vars *vars, struct Qdisc *sch)
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{
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+ struct fq_codel_sched_data *q = qdisc_priv(sch);
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struct fq_codel_flow *flow;
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struct sk_buff *skb = NULL;
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flow = container_of(vars, struct fq_codel_flow, cvars);
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if (flow->head) {
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skb = dequeue_head(flow);
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- sch->qstats.backlog -= qdisc_pkt_len(skb);
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+ q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb);
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sch->q.qlen--;
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}
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return skb;
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@@ -256,7 +257,7 @@ begin:
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prev_ecn_mark = q->cstats.ecn_mark;
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skb = codel_dequeue(sch, &q->cparams, &flow->cvars, &q->cstats,
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- dequeue, &q->backlogs[flow - q->flows]);
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+ dequeue);
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flow->dropped += q->cstats.drop_count - prev_drop_count;
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flow->dropped += q->cstats.ecn_mark - prev_ecn_mark;
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