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authorCong Wang <xiyou.wangcong@gmail.com>2018-01-25 18:26:23 -0800
committerDavid S. Miller <davem@davemloft.net>2018-01-29 12:42:15 -0500
commit48bfd55e7e4149a304e89c1999436cf52d094a27 (patch)
tree6318e75ea99c74a81622ebe82ee2c71c9338baf4 /net/sched/sch_generic.c
parent6a643ddb5624be7e0694d49f5765a8d41c1ab6d0 (diff)
downloadlinux-sh-48bfd55e7e4149a304e89c1999436cf52d094a27.tar.gz
net_sched: plug in qdisc ops change_tx_queue_len
Introduce a new qdisc ops ->change_tx_queue_len() so that each qdisc could decide how to implement this if it wants. Previously we simply read dev->tx_queue_len, after pfifo_fast switches to skb array, we need this API to resize the skb array when we change dev->tx_queue_len. To avoid handling race conditions with TX BH, we need to deactivate all TX queues before change the value and bring them back after we are done, this also makes implementation easier. Cc: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/sch_generic.c')
-rw-r--r--net/sched/sch_generic.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 1816bde47256..08f9fa27e06e 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -1178,6 +1178,39 @@ void dev_deactivate(struct net_device *dev)
}
EXPORT_SYMBOL(dev_deactivate);
+static int qdisc_change_tx_queue_len(struct net_device *dev,
+ struct netdev_queue *dev_queue)
+{
+ struct Qdisc *qdisc = dev_queue->qdisc_sleeping;
+ const struct Qdisc_ops *ops = qdisc->ops;
+
+ if (ops->change_tx_queue_len)
+ return ops->change_tx_queue_len(qdisc, dev->tx_queue_len);
+ return 0;
+}
+
+int dev_qdisc_change_tx_queue_len(struct net_device *dev)
+{
+ bool up = dev->flags & IFF_UP;
+ unsigned int i;
+ int ret = 0;
+
+ if (up)
+ dev_deactivate(dev);
+
+ for (i = 0; i < dev->num_tx_queues; i++) {
+ ret = qdisc_change_tx_queue_len(dev, &dev->_tx[i]);
+
+ /* TODO: revert changes on a partial failure */
+ if (ret)
+ break;
+ }
+
+ if (up)
+ dev_activate(dev);
+ return ret;
+}
+
static void dev_init_scheduler_queue(struct net_device *dev,
struct netdev_queue *dev_queue,
void *_qdisc)