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author | Eric Dumazet <eric.dumazet@gmail.com> | 2010-12-20 13:18:16 -0800 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2010-12-20 13:18:16 -0800 |
commit | aa3e219997e4b949be4199660936099ded0b401f (patch) | |
tree | e463d695dbf0e92f7fd2c6b3132bbb9c38493829 /net | |
parent | 914e5cea14b2e4651cdb0707e0936b43246deda0 (diff) | |
download | op-kernel-dev-aa3e219997e4b949be4199660936099ded0b401f.zip op-kernel-dev-aa3e219997e4b949be4199660936099ded0b401f.tar.gz |
net_sched: sch_sfq: fix allot handling
When deploying SFQ/IFB here at work, I found the allot management was
pretty wrong in sfq, even changing allot from short to int...
We should init allot for each new flow, not using a previous value found
in slot.
Before patch, I saw bursts of several packets per flow, apparently
denying the default "quantum 1514" limit I had on my SFQ class.
class sfq 11:1 parent 11:
(dropped 0, overlimits 0 requeues 0)
backlog 0b 7p requeues 0
allot 11546
class sfq 11:46 parent 11:
(dropped 0, overlimits 0 requeues 0)
backlog 0b 1p requeues 0
allot -23873
class sfq 11:78 parent 11:
(dropped 0, overlimits 0 requeues 0)
backlog 0b 5p requeues 0
allot 11393
After patch, better fairness among each flow, allot limit being
respected, allot is positive :
class sfq 11:e parent 11:
(dropped 0, overlimits 0 requeues 86)
backlog 0b 3p requeues 86
allot 596
class sfq 11:94 parent 11:
(dropped 0, overlimits 0 requeues 0)
backlog 0b 3p requeues 0
allot 1468
class sfq 11:a4 parent 11:
(dropped 0, overlimits 0 requeues 0)
backlog 0b 4p requeues 0
allot 650
class sfq 11:bb parent 11:
(dropped 0, overlimits 0 requeues 0)
backlog 0b 3p requeues 0
allot 596
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r-- | net/sched/sch_sfq.c | 20 |
1 files changed, 8 insertions, 12 deletions
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c index 3cf478d..7150705 100644 --- a/net/sched/sch_sfq.c +++ b/net/sched/sch_sfq.c @@ -270,7 +270,6 @@ static unsigned int sfq_drop(struct Qdisc *sch) /* It is difficult to believe, but ALL THE SLOTS HAVE LENGTH 1. */ d = q->next[q->tail]; q->next[q->tail] = q->next[d]; - q->allot[q->next[d]] += q->quantum; skb = q->qs[d].prev; len = qdisc_pkt_len(skb); __skb_unlink(skb, &q->qs[d]); @@ -321,14 +320,13 @@ sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch) sfq_inc(q, x); if (q->qs[x].qlen == 1) { /* The flow is new */ if (q->tail == SFQ_DEPTH) { /* It is the first flow */ - q->tail = x; q->next[x] = x; - q->allot[x] = q->quantum; } else { q->next[x] = q->next[q->tail]; q->next[q->tail] = x; - q->tail = x; } + q->tail = x; + q->allot[x] = q->quantum; } if (++sch->q.qlen <= q->limit) { sch->bstats.bytes += qdisc_pkt_len(skb); @@ -359,13 +357,13 @@ sfq_dequeue(struct Qdisc *sch) { struct sfq_sched_data *q = qdisc_priv(sch); struct sk_buff *skb; - sfq_index a, old_a; + sfq_index a, next_a; /* No active slots */ if (q->tail == SFQ_DEPTH) return NULL; - a = old_a = q->next[q->tail]; + a = q->next[q->tail]; /* Grab packet */ skb = __skb_dequeue(&q->qs[a]); @@ -376,17 +374,15 @@ sfq_dequeue(struct Qdisc *sch) /* Is the slot empty? */ if (q->qs[a].qlen == 0) { q->ht[q->hash[a]] = SFQ_DEPTH; - a = q->next[a]; - if (a == old_a) { + next_a = q->next[a]; + if (a == next_a) { q->tail = SFQ_DEPTH; return skb; } - q->next[q->tail] = a; - q->allot[a] += q->quantum; + q->next[q->tail] = next_a; } else if ((q->allot[a] -= qdisc_pkt_len(skb)) <= 0) { - q->tail = a; - a = q->next[a]; q->allot[a] += q->quantum; + q->tail = a; } return skb; } |