path: root/net
diff options
authorDavid S. Miller <davem@davemloft.net>2008-08-13 15:18:38 -0700
committerDavid S. Miller <davem@davemloft.net>2008-08-13 15:18:38 -0700
commitb9a3b1102bc80b4044224494100f67de132d5448 (patch)
tree26d693207ad5c5e9ea79a2b21de48b1e409f628e /net
parent26b284de54a5ca3dfbe2fd9a51ac1923e80085a2 (diff)
pkt_sched: Fix queue quiescence testing in dev_deactivate().
Based upon discussions with Jarek P. and Herbert Xu. First, we're testing the wrong qdisc. We just reset the device queue qdiscs to &noop_qdisc and checking it's state is completely pointless here. We want to wait until the previous qdisc that was sitting at the ->qdisc pointer is not busy any more. And that would be ->qdisc_sleeping. Because of how we propagate the samples qdisc pointer down into qdisc_run and friends via per-cpu ->output_queue and netif_schedule, we have to wait also for the __QDISC_STATE_SCHED bit to clear as well. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
1 files changed, 6 insertions, 5 deletions
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 7cf83b37459d..468574682caa 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -647,7 +647,7 @@ static void dev_deactivate_queue(struct net_device *dev,
-static bool some_qdisc_is_running(struct net_device *dev, int lock)
+static bool some_qdisc_is_busy(struct net_device *dev, int lock)
unsigned int i;
@@ -658,13 +658,14 @@ static bool some_qdisc_is_running(struct net_device *dev, int lock)
int val;
dev_queue = netdev_get_tx_queue(dev, i);
- q = dev_queue->qdisc;
+ q = dev_queue->qdisc_sleeping;
root_lock = qdisc_lock(q);
if (lock)
- val = test_bit(__QDISC_STATE_RUNNING, &q->state);
+ val = (test_bit(__QDISC_STATE_RUNNING, &q->state) ||
+ test_bit(__QDISC_STATE_SCHED, &q->state));
if (lock)
@@ -689,14 +690,14 @@ void dev_deactivate(struct net_device *dev)
/* Wait for outstanding qdisc_run calls. */
do {
- while (some_qdisc_is_running(dev, 0))
+ while (some_qdisc_is_busy(dev, 0))
* Double-check inside queue lock to ensure that all effects
* of the queue run are visible when we return.
- running = some_qdisc_is_running(dev, 1);
+ running = some_qdisc_is_busy(dev, 1);
* The running flag should never be set at this point because

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