From f07d1501292b3b0d3276ee0e537005526a45e242 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Fri, 12 Sep 2008 17:57:23 -0700 Subject: [PATCH] multiq: Further multiqueue cleanup This patch resolves a few issues found with multiq including wording suggestions and a problem seen in the allocation of queues. Signed-off-by: Alexander Duyck Signed-off-by: Jeff Kirsher Signed-off-by: David S. Miller --- Documentation/networking/multiqueue.txt | 14 +++++++------- net/sched/sch_multiq.c | 13 +++++++++---- 2 files changed, 16 insertions(+), 11 deletions(-) diff --git a/Documentation/networking/multiqueue.txt b/Documentation/networking/multiqueue.txt index 8c2b06b77f61..4caa0e314cc2 100644 --- a/Documentation/networking/multiqueue.txt +++ b/Documentation/networking/multiqueue.txt @@ -29,15 +29,15 @@ Section 2: Qdisc support for multiqueue devices ----------------------------------------------- -Currently two qdiscs support multiqueue devices. The first is the default -pfifo_fast qdisc. This qdisc supports one qdisc per hardware queue. A new -round-robin qdisc, sch_multiq also supports multiple hardware queues. The +Currently two qdiscs are optimized for multiqueue devices. The first is the +default pfifo_fast qdisc. This qdisc supports one qdisc per hardware queue. +A new round-robin qdisc, sch_multiq also supports multiple hardware queues. The qdisc is responsible for classifying the skb's and then directing the skb's to bands and queues based on the value in skb->queue_mapping. Use this field in the base driver to determine which queue to send the skb to. -sch_multiq has been added for hardware that wishes to avoid unnecessary -requeuing. It will cycle though the bands and verify that the hardware queue +sch_multiq has been added for hardware that wishes to avoid head-of-line +blocking. It will cycle though the bands and verify that the hardware queue associated with the band is not stopped prior to dequeuing a packet. On qdisc load, the number of bands is based on the number of queues on the @@ -63,8 +63,8 @@ band 1 => queue 1 band 2 => queue 2 band 3 => queue 3 -Traffic will begin flowing through each queue if your base device has either -the default simple_tx_hash or a custom netdev->select_queue() defined. +Traffic will begin flowing through each queue based on either the simple_tx_hash +function or based on netdev->select_queue() if you have it defined. The behavior of tc filters remains the same. However a new tc action, skbedit, has been added. Assuming you wanted to route all traffic to a diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c index 49a8b67ed3b8..5d9cd68e91d1 100644 --- a/net/sched/sch_multiq.c +++ b/net/sched/sch_multiq.c @@ -214,8 +214,8 @@ static int multiq_tune(struct Qdisc *sch, struct nlattr *opt) sch_tree_lock(sch); q->bands = qopt->bands; for (i = q->bands; i < q->max_bands; i++) { - struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc); - if (child != &noop_qdisc) { + if (q->queues[i] != &noop_qdisc) { + struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc); qdisc_tree_decrease_qlen(child, child->q.qlen); qdisc_destroy(child); } @@ -250,7 +250,7 @@ static int multiq_tune(struct Qdisc *sch, struct nlattr *opt) static int multiq_init(struct Qdisc *sch, struct nlattr *opt) { struct multiq_sched_data *q = qdisc_priv(sch); - int i; + int i, err; q->queues = NULL; @@ -265,7 +265,12 @@ static int multiq_init(struct Qdisc *sch, struct nlattr *opt) for (i = 0; i < q->max_bands; i++) q->queues[i] = &noop_qdisc; - return multiq_tune(sch, opt); + err = multiq_tune(sch,opt); + + if (err) + kfree(q->queues); + + return err; } static int multiq_dump(struct Qdisc *sch, struct sk_buff *skb) -- 2.30.2