diff options
| author | Maxim Mikityanskiy <maximmi@mellanox.com> | 2021-01-19 14:08:11 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-01-22 20:41:29 -0800 |
| commit | ca1e4ab199933e1af3f9a86d31060b7f9181c3fc (patch) | |
| tree | be325e07b9bbe53aae8275e7fcc398524c7b06b7 /include/net/sch_generic.h | |
| parent | 04a886372a2052078fa72b4ecb23f0ac8094f654 (diff) | |
| download | lwn-ca1e4ab199933e1af3f9a86d31060b7f9181c3fc.tar.gz lwn-ca1e4ab199933e1af3f9a86d31060b7f9181c3fc.zip | |
net: sched: Add multi-queue support to sch_tree_lock
The existing qdiscs that set TCQ_F_MQROOT don't use sch_tree_lock.
However, hardware-offloaded HTB will start setting this flag while also
using sch_tree_lock.
The current implementation of sch_tree_lock basically locks on
qdisc->dev_queue->qdisc, and it works fine when the tree is attached to
some queue. However, it's not the case for MQROOT qdiscs: such a qdisc
is the root itself, and its dev_queue just points to queue 0, while not
actually being used, because there are real per-queue qdiscs.
This patch changes the logic of sch_tree_lock and sch_tree_unlock to
lock the qdisc itself if it's the MQROOT.
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/net/sch_generic.h')
| -rw-r--r-- | include/net/sch_generic.h | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index e7bee99aebce..296919010552 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -552,14 +552,20 @@ static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc) return qdisc->dev_queue->dev; } -static inline void sch_tree_lock(const struct Qdisc *q) +static inline void sch_tree_lock(struct Qdisc *q) { - spin_lock_bh(qdisc_root_sleeping_lock(q)); + if (q->flags & TCQ_F_MQROOT) + spin_lock_bh(qdisc_lock(q)); + else + spin_lock_bh(qdisc_root_sleeping_lock(q)); } -static inline void sch_tree_unlock(const struct Qdisc *q) +static inline void sch_tree_unlock(struct Qdisc *q) { - spin_unlock_bh(qdisc_root_sleeping_lock(q)); + if (q->flags & TCQ_F_MQROOT) + spin_unlock_bh(qdisc_lock(q)); + else + spin_unlock_bh(qdisc_root_sleeping_lock(q)); } extern struct Qdisc noop_qdisc; |