This patch addresses the issue of serialization between the main rx path and various reorder release timers. <http://www.spinics.net/lists/linux-wireless/msg57214.html> It converts the previously local "frames" queue into a global rx queue [rx_skb_queue]. This way, everyone (be it the main rx-path or some reorder release timeout) can add frames to it. Only one active rx handler worker [ieee80211_rx_handlers] is needed. All other threads which have lost the race of "runnning_rx_handler" can now simply "return", knowing that the thread who had the "edge" will also take care of their workload. Signed-off-by: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx> --- net/mac80211/ieee80211_i.h | 9 +++++ net/mac80211/main.c | 3 ++ net/mac80211/rx.c | 80 ++++++++++++++++++++----------------------- 3 files changed, 49 insertions(+), 43 deletions(-) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index a0cf5ab..acc1299 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -774,6 +774,15 @@ struct ieee80211_local { struct sk_buff_head skb_queue; struct sk_buff_head skb_queue_unreliable; + /* + * Internal FIFO queue which is shared between multiple rx path + * stages. Its main task is to provide a serialization mechanism, + * so all rx handlers can enjoy having exclusive access to their + * private data structures. + */ + struct sk_buff_head rx_skb_queue; + bool running_rx_handler; /* protected by rx_skb_queue.lock */ + /* Station data */ /* * The mutex only protects the list and counter, diff --git a/net/mac80211/main.c b/net/mac80211/main.c index 32e58ee..485d36b 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -569,6 +569,8 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len, spin_lock_init(&local->filter_lock); spin_lock_init(&local->queue_stop_reason_lock); + skb_queue_head_init(&local->rx_skb_queue); + INIT_DELAYED_WORK(&local->scan_work, ieee80211_scan_work); ieee80211_work_init(local); @@ -917,6 +919,7 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw) wiphy_warn(local->hw.wiphy, "skb_queue not empty\n"); skb_queue_purge(&local->skb_queue); skb_queue_purge(&local->skb_queue_unreliable); + skb_queue_purge(&local->rx_skb_queue); destroy_workqueue(local->workqueue); wiphy_unregister(local->hw.wiphy); diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 5e9d3bc..62a82ec 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -533,9 +533,9 @@ static inline u16 seq_sub(u16 sq1, u16 sq2) static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw, struct tid_ampdu_rx *tid_agg_rx, - int index, - struct sk_buff_head *frames) + int index) { + struct ieee80211_local *local = hw_to_local(hw); struct sk_buff *skb = tid_agg_rx->reorder_buf[index]; lockdep_assert_held(&tid_agg_rx->reorder_lock); @@ -546,7 +546,7 @@ static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw, /* release the frame from the reorder ring buffer */ tid_agg_rx->stored_mpdu_num--; tid_agg_rx->reorder_buf[index] = NULL; - __skb_queue_tail(frames, skb); + skb_queue_tail(&local->rx_skb_queue, skb); no_frame: tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num); @@ -554,8 +554,7 @@ no_frame: static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw, struct tid_ampdu_rx *tid_agg_rx, - u16 head_seq_num, - struct sk_buff_head *frames) + u16 head_seq_num) { int index; @@ -564,7 +563,7 @@ static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw, while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) { index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size; - ieee80211_release_reorder_frame(hw, tid_agg_rx, index, frames); + ieee80211_release_reorder_frame(hw, tid_agg_rx, index); } } @@ -580,8 +579,7 @@ static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw, #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10) static void ieee80211_sta_reorder_release(struct ieee80211_hw *hw, - struct tid_ampdu_rx *tid_agg_rx, - struct sk_buff_head *frames) + struct tid_ampdu_rx *tid_agg_rx) { int index, j; @@ -612,8 +610,7 @@ static void ieee80211_sta_reorder_release(struct ieee80211_hw *hw, wiphy_debug(hw->wiphy, "release an RX reorder frame due to timeout on earlier frames\n"); #endif - ieee80211_release_reorder_frame(hw, tid_agg_rx, - j, frames); + ieee80211_release_reorder_frame(hw, tid_agg_rx, j); /* * Increment the head seq# also for the skipped slots. @@ -623,7 +620,7 @@ static void ieee80211_sta_reorder_release(struct ieee80211_hw *hw, skipped = 0; } } else while (tid_agg_rx->reorder_buf[index]) { - ieee80211_release_reorder_frame(hw, tid_agg_rx, index, frames); + ieee80211_release_reorder_frame(hw, tid_agg_rx, index); index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size; } @@ -679,8 +676,7 @@ set_release_timer: */ static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw, struct tid_ampdu_rx *tid_agg_rx, - struct sk_buff *skb, - struct sk_buff_head *frames) + struct sk_buff *skb) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; u16 sc = le16_to_cpu(hdr->seq_ctrl); @@ -707,8 +703,7 @@ static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw, if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) { head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size)); /* release stored frames up to new head to stack */ - ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num, - frames); + ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num); } /* Now the new frame is always in the range of the reordering buffer */ @@ -736,7 +731,7 @@ static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw, tid_agg_rx->reorder_buf[index] = skb; tid_agg_rx->reorder_time[index] = jiffies; tid_agg_rx->stored_mpdu_num++; - ieee80211_sta_reorder_release(hw, tid_agg_rx, frames); + ieee80211_sta_reorder_release(hw, tid_agg_rx); out: spin_unlock(&tid_agg_rx->reorder_lock); @@ -747,8 +742,7 @@ static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw, * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns * true if the MPDU was buffered, false if it should be processed. */ -static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx, - struct sk_buff_head *frames) +static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx) { struct sk_buff *skb = rx->skb; struct ieee80211_local *local = rx->local; @@ -803,11 +797,11 @@ static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx, * sure that we cannot get to it any more before doing * anything with it. */ - if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb, frames)) + if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb)) return; dont_reorder: - __skb_queue_tail(frames, skb); + skb_queue_tail(&local->rx_skb_queue, skb); } static ieee80211_rx_result debug_noinline @@ -1930,7 +1924,7 @@ ieee80211_rx_h_data(struct ieee80211_rx_data *rx) } static ieee80211_rx_result debug_noinline -ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames) +ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx) { struct ieee80211_local *local = rx->local; struct ieee80211_hw *hw = &local->hw; @@ -1970,8 +1964,7 @@ ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames) spin_lock(&tid_agg_rx->reorder_lock); /* release stored frames up to start of BAR */ - ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num, - frames); + ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num); spin_unlock(&tid_agg_rx->reorder_lock); kfree_skb(skb); @@ -2488,8 +2481,7 @@ static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx, } } -static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx, - struct sk_buff_head *frames) +static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx) { ieee80211_rx_result res = RX_DROP_MONITOR; struct sk_buff *skb; @@ -2501,7 +2493,15 @@ static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx, goto rxh_next; \ } while (0); - while ((skb = __skb_dequeue(frames))) { + spin_lock(&rx->local->rx_skb_queue.lock); + if (rx->local->running_rx_handler) + goto unlock; + + rx->local->running_rx_handler = true; + + while ((skb = __skb_dequeue(&rx->local->rx_skb_queue))) { + spin_unlock(&rx->local->rx_skb_queue.lock); + /* * all the other fields are valid across frames * that belong to an aMPDU since they are on the @@ -2524,12 +2524,7 @@ static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx, CALL_RXH(ieee80211_rx_h_mesh_fwding); #endif CALL_RXH(ieee80211_rx_h_data) - - /* special treatment -- needs the queue */ - res = ieee80211_rx_h_ctrl(rx, frames); - if (res != RX_CONTINUE) - goto rxh_next; - + CALL_RXH(ieee80211_rx_h_ctrl); CALL_RXH(ieee80211_rx_h_mgmt_check) CALL_RXH(ieee80211_rx_h_action) CALL_RXH(ieee80211_rx_h_userspace_mgmt) @@ -2538,18 +2533,20 @@ static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx, rxh_next: ieee80211_rx_handlers_result(rx, res); - + spin_lock(&rx->local->rx_skb_queue.lock); #undef CALL_RXH } + + rx->local->running_rx_handler = false; + + unlock: + spin_unlock(&rx->local->rx_skb_queue.lock); } static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx) { - struct sk_buff_head reorder_release; ieee80211_rx_result res = RX_DROP_MONITOR; - __skb_queue_head_init(&reorder_release); - #define CALL_RXH(rxh) \ do { \ res = rxh(rx); \ @@ -2560,9 +2557,9 @@ static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx) CALL_RXH(ieee80211_rx_h_passive_scan) CALL_RXH(ieee80211_rx_h_check) - ieee80211_rx_reorder_ampdu(rx, &reorder_release); + ieee80211_rx_reorder_ampdu(rx); - ieee80211_rx_handlers(rx, &reorder_release); + ieee80211_rx_handlers(rx); return; rxh_next: @@ -2577,7 +2574,6 @@ static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx) */ void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid) { - struct sk_buff_head frames; struct ieee80211_rx_data rx = { .sta = sta, .sdata = sta->sdata, @@ -2590,13 +2586,11 @@ void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid) if (!tid_agg_rx) return; - __skb_queue_head_init(&frames); - spin_lock(&tid_agg_rx->reorder_lock); - ieee80211_sta_reorder_release(&sta->local->hw, tid_agg_rx, &frames); + ieee80211_sta_reorder_release(&sta->local->hw, tid_agg_rx); spin_unlock(&tid_agg_rx->reorder_lock); - ieee80211_rx_handlers(&rx, &frames); + ieee80211_rx_handlers(&rx); } /* main receive path */ -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
