Commit f07d1501292b3b0d3276ee0e537005526a45e242
Committed by
David S. Miller
David S. Miller
1 parent
67333bb567
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master
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20 other branches
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 <alexander.h.duyck@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Showing 2 changed files with 16 additions and 11 deletions Side-by-side Diff
Documentation/networking/multiqueue.txt
| ... | ... | @@ -29,15 +29,15 @@ |
| 29 | 29 | |
| 30 | 30 | ----------------------------------------------- |
| 31 | 31 | |
| 32 | -Currently two qdiscs support multiqueue devices. The first is the default | |
| 33 | -pfifo_fast qdisc. This qdisc supports one qdisc per hardware queue. A new | |
| 34 | -round-robin qdisc, sch_multiq also supports multiple hardware queues. The | |
| 32 | +Currently two qdiscs are optimized for multiqueue devices. The first is the | |
| 33 | +default pfifo_fast qdisc. This qdisc supports one qdisc per hardware queue. | |
| 34 | +A new round-robin qdisc, sch_multiq also supports multiple hardware queues. The | |
| 35 | 35 | qdisc is responsible for classifying the skb's and then directing the skb's to |
| 36 | 36 | bands and queues based on the value in skb->queue_mapping. Use this field in |
| 37 | 37 | the base driver to determine which queue to send the skb to. |
| 38 | 38 | |
| 39 | -sch_multiq has been added for hardware that wishes to avoid unnecessary | |
| 40 | -requeuing. It will cycle though the bands and verify that the hardware queue | |
| 39 | +sch_multiq has been added for hardware that wishes to avoid head-of-line | |
| 40 | +blocking. It will cycle though the bands and verify that the hardware queue | |
| 41 | 41 | associated with the band is not stopped prior to dequeuing a packet. |
| 42 | 42 | |
| 43 | 43 | On qdisc load, the number of bands is based on the number of queues on the |
| ... | ... | @@ -63,8 +63,8 @@ |
| 63 | 63 | band 2 => queue 2 |
| 64 | 64 | band 3 => queue 3 |
| 65 | 65 | |
| 66 | -Traffic will begin flowing through each queue if your base device has either | |
| 67 | -the default simple_tx_hash or a custom netdev->select_queue() defined. | |
| 66 | +Traffic will begin flowing through each queue based on either the simple_tx_hash | |
| 67 | +function or based on netdev->select_queue() if you have it defined. | |
| 68 | 68 | |
| 69 | 69 | The behavior of tc filters remains the same. However a new tc action, |
| 70 | 70 | skbedit, has been added. Assuming you wanted to route all traffic to a |
net/sched/sch_multiq.c
| ... | ... | @@ -214,8 +214,8 @@ |
| 214 | 214 | sch_tree_lock(sch); |
| 215 | 215 | q->bands = qopt->bands; |
| 216 | 216 | for (i = q->bands; i < q->max_bands; i++) { |
| 217 | - struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc); | |
| 218 | - if (child != &noop_qdisc) { | |
| 217 | + if (q->queues[i] != &noop_qdisc) { | |
| 218 | + struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc); | |
| 219 | 219 | qdisc_tree_decrease_qlen(child, child->q.qlen); |
| 220 | 220 | qdisc_destroy(child); |
| 221 | 221 | } |
| ... | ... | @@ -250,7 +250,7 @@ |
| 250 | 250 | static int multiq_init(struct Qdisc *sch, struct nlattr *opt) |
| 251 | 251 | { |
| 252 | 252 | struct multiq_sched_data *q = qdisc_priv(sch); |
| 253 | - int i; | |
| 253 | + int i, err; | |
| 254 | 254 | |
| 255 | 255 | q->queues = NULL; |
| 256 | 256 | |
| ... | ... | @@ -265,7 +265,12 @@ |
| 265 | 265 | for (i = 0; i < q->max_bands; i++) |
| 266 | 266 | q->queues[i] = &noop_qdisc; |
| 267 | 267 | |
| 268 | - return multiq_tune(sch, opt); | |
| 268 | + err = multiq_tune(sch,opt); | |
| 269 | + | |
| 270 | + if (err) | |
| 271 | + kfree(q->queues); | |
| 272 | + | |
| 273 | + return err; | |
| 269 | 274 | } |
| 270 | 275 | |
| 271 | 276 | static int multiq_dump(struct Qdisc *sch, struct sk_buff *skb) |