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| author | Javier Cardona <javier@cozybit.com> | 2011-11-03 21:11:10 -0700 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2011-11-09 16:01:02 -0500 |
| commit | f3011cf9deb689bd68279c728c501a4166983c19 (patch) | |
| tree | 7d9945a2934c6de78063c358a6d350af8b6a19a9 /net | |
| parent | 7e1e386421e2ec7804b77f2c1c8e2517e82ecb7e (diff) | |
| download | linux-stable-f3011cf9deb689bd68279c728c501a4166983c19.tar.gz linux-stable-f3011cf9deb689bd68279c728c501a4166983c19.tar.bz2 linux-stable-f3011cf9deb689bd68279c728c501a4166983c19.zip | |
mac80211: Avoid filling up mesh preq queue with redundant requests
Don't accept redundant PREQs for a given destination. This fixes a
problem under high load:
kernel: [20386.250913] mesh_queue_preq: 235 callbacks suppressed
kernel: [20386.253335] Mesh HWMP (mesh0): PREQ node queue full
kernel: [20386.253352] Mesh HWMP (mesh0): PREQ node queue full
(...)
The 802.11s protocol has a provision to limit the rate of path requests
(PREQs) are transmitted (dot11MeshHWMPpreqMinInterval) but there was no
limit on the rate at which PREQs were being queued up. There is a valid
reason for queuing PREQs: this way we can even out PREQ bursts. But
queueing multiple PREQs for the same destination is useless.
Reported-by: Pedro Larbig <pedro.larbig@carhs.de>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/mac80211/mesh.h | 3 | ||||
| -rw-r--r-- | net/mac80211/mesh_hwmp.c | 15 |
2 files changed, 16 insertions, 2 deletions
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h index 0f2c4e69e217..622cc96eb4de 100644 --- a/net/mac80211/mesh.h +++ b/net/mac80211/mesh.h @@ -31,6 +31,8 @@ * @MESH_PATH_FIXED: the mesh path has been manually set and should not be * modified * @MESH_PATH_RESOLVED: the mesh path can has been resolved + * @MESH_PATH_REQ_QUEUED: there is an unsent path request for this destination + * already queued up, waiting for the discovery process to start. * * MESH_PATH_RESOLVED is used by the mesh path timer to * decide when to stop or cancel the mesh path discovery. @@ -41,6 +43,7 @@ enum mesh_path_flags { MESH_PATH_SN_VALID = BIT(2), MESH_PATH_FIXED = BIT(3), MESH_PATH_RESOLVED = BIT(4), + MESH_PATH_REQ_QUEUED = BIT(5), }; /** diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c index 9a1f8bbc49b8..b22b223ccde1 100644 --- a/net/mac80211/mesh_hwmp.c +++ b/net/mac80211/mesh_hwmp.c @@ -867,9 +867,19 @@ static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) return; } + spin_lock_bh(&mpath->state_lock); + if (mpath->flags & MESH_PATH_REQ_QUEUED) { + spin_unlock_bh(&mpath->state_lock); + spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); + return; + } + memcpy(preq_node->dst, mpath->dst, ETH_ALEN); preq_node->flags = flags; + mpath->flags |= MESH_PATH_REQ_QUEUED; + spin_unlock_bh(&mpath->state_lock); + list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); ++ifmsh->preq_queue_len; spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); @@ -921,6 +931,7 @@ void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) goto enddiscovery; spin_lock_bh(&mpath->state_lock); + mpath->flags &= ~MESH_PATH_REQ_QUEUED; if (preq_node->flags & PREQ_Q_F_START) { if (mpath->flags & MESH_PATH_RESOLVING) { spin_unlock_bh(&mpath->state_lock); @@ -1028,8 +1039,7 @@ int mesh_nexthop_lookup(struct sk_buff *skb, mesh_queue_preq(mpath, PREQ_Q_F_START); } - if (skb_queue_len(&mpath->frame_queue) >= - MESH_FRAME_QUEUE_LEN) + if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN) skb_to_free = skb_dequeue(&mpath->frame_queue); info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; @@ -1061,6 +1071,7 @@ void mesh_path_timer(unsigned long data) } else if (mpath->discovery_retries < max_preq_retries(sdata)) { ++mpath->discovery_retries; mpath->discovery_timeout *= 2; + mpath->flags &= ~MESH_PATH_REQ_QUEUED; spin_unlock_bh(&mpath->state_lock); mesh_queue_preq(mpath, 0); } else { |