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>
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index 0f2c4e6..622cc96 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 @@
MESH_PATH_SN_VALID = BIT(2),
MESH_PATH_FIXED = BIT(3),
MESH_PATH_RESOLVED = BIT(4),
+ MESH_PATH_REQ_QUEUED = BIT(5),
};
/**