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>
This commit is contained in:
Javier Cardona
2011-11-03 21:11:10 -07:00
committed by John W. Linville
parent 7e1e386421
commit f3011cf9de
2 changed files with 16 additions and 2 deletions

View File

@@ -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),
};
/**