diff options
| author |   Felix Fietkau <nbd@openwrt.org> | 2012-03-18 22:58:06 +0100 |
|---|---|---|
| committer |   John W. Linville <linville@tuxdriver.com> | 2012-04-09 16:09:36 -0400 |
| commit | 12d3952fc4a1cd96234bc7023bf7eefeb0bb6355 (patch) | |
| tree | 5c3437e1f996a5c772b286530a3fce547a7d40f2 /net/mac80211/agg-tx.c | |
| parent | mac80211: reduce code duplication in debugfs code (diff) | |
| download | linux-dev-12d3952fc4a1cd96234bc7023bf7eefeb0bb6355.tar.xz linux-dev-12d3952fc4a1cd96234bc7023bf7eefeb0bb6355.zip | |
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>
Diffstat (limited to 'net/mac80211/agg-tx.c')
| -rw-r--r-- | net/mac80211/agg-tx.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c index 76be61744198..9628a1892441 100644 --- a/net/mac80211/agg-tx.c +++ b/net/mac80211/agg-tx.c @@ -417,6 +417,18 @@ static void sta_tx_agg_session_timer_expired(unsigned long data) u8 *timer_to_id = ptid - *ptid; struct sta_info *sta = container_of(timer_to_id, struct sta_info, timer_to_tid[0]); + struct tid_ampdu_tx *tid_tx; + unsigned long timeout; + + tid_tx = rcu_dereference_protected_tid_tx(sta, *ptid); + if (!tid_tx) + return; + + timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout); + if (time_is_after_jiffies(timeout)) { + mod_timer(&tid_tx->session_timer, timeout); + return; + } #ifdef CONFIG_MAC80211_HT_DEBUG printk(KERN_DEBUG "tx session timer expired on tid %d\n", (u16)*ptid); @@ -542,7 +554,7 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid, /* tx timer */ tid_tx->session_timer.function = sta_tx_agg_session_timer_expired; tid_tx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid]; - init_timer(&tid_tx->session_timer); + init_timer_deferrable(&tid_tx->session_timer); /* assign a dialog token */ sta->ampdu_mlme.dialog_token_allocator++; @@ -884,9 +896,11 @@ void ieee80211_process_addba_resp(struct ieee80211_local *local, sta->ampdu_mlme.addba_req_num[tid] = 0; - if (tid_tx->timeout) + if (tid_tx->timeout) { mod_timer(&tid_tx->session_timer, TU_TO_EXP_TIME(tid_tx->timeout)); + tid_tx->last_tx = jiffies; + } } else { ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR, |