mac80211: optimize aggregation session timeout handling
Calling mod_timer from the rx/tx hotpath is somewhat expensive, and the
timeout doesn't need to be so precise.
Switch to a different strategy: Schedule the timer initially, store jiffies
of all last rx/tx activity which would previously modify the timer, and
let the timer re-arm itself after checking the last rx/tx timestamp.
Make the session timers deferrable to avoid causing extra wakeups on systems
running on battery.
This visibly reduces CPU load under high network load on small embedded
systems.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index bcfe8c7..8da3b36 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -793,8 +793,7 @@
/* reset session timer */
if (tid_agg_rx->timeout)
- mod_timer(&tid_agg_rx->session_timer,
- TU_TO_EXP_TIME(tid_agg_rx->timeout));
+ tid_agg_rx->last_rx = jiffies;
/* if this mpdu is fragmented - terminate rx aggregation session */
sc = le16_to_cpu(hdr->seq_ctrl);
