Small devices can run out of memory from queueing too many packets. If
VHT is not supported by the PHY, having more than 4 MBytes of total
queue in the TXQ intermediate queues is not needed, and so we can safely
limit the memory usage in these cases and avoid OOM.
Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxx>
---
net/mac80211/tx.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 1ff08be..82f41fc 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1434,6 +1434,8 @@ int ieee80211_txq_setup_flows(struct ieee80211_local *local)
struct fq *fq = &local->fq;
int ret;
int i;
+ bool supp_vht = false;
+ enum nl80211_band band;
if (!local->ops->wake_tx_queue)
return 0;
@@ -1442,6 +1444,22 @@ int ieee80211_txq_setup_flows(struct ieee80211_local *local)
if (ret)
return ret;
+ /*
+ * If the hardware doesn't support VHT, it is safe to limit the maximum
+ * queue size. 4 Mbytes is 64 max-size aggregates in 802.11n.
+ */
+ for (band = 0; band < NUM_NL80211_BANDS; band++) {
+ struct ieee80211_supported_band *sband;
+
+ sband = local->hw.wiphy->bands[band];
+ if (!sband)
+ continue;
+
+ supp_vht = supp_vht || sband->vht_cap.vht_supported;
+ }
+ if (!supp_vht)
+ fq->memory_limit = 4 << 20; /* 4 Mbytes */
+
codel_params_init(&local->cparams);
local->cparams.interval = MS2TIME(100);
local->cparams.target = MS2TIME(20);
--
2.9.3
