Re: hung task in mac80211
From: Stefano Brivio <hidden>
Date: 2017-09-06 14:27:57
Also in:
lkml, netdev
Subsystem:
mac80211, the rest · Maintainers:
Johannes Berg, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2017-09-06 · Re: hung task in mac80211 · Johannes Berg <johannes@sipsolutions.net>
- 2017-09-06 · Re: hung task in mac80211 · Stefano Brivio <hidden>
- 2017-09-06 · Re: hung task in mac80211 · Johannes Berg <johannes@sipsolutions.net>
- 2017-09-06 · Re: hung task in mac80211 · Stefano Brivio <hidden>
- 2017-09-06 · Re: hung task in mac80211 · Johannes Berg <johannes@sipsolutions.net>
On Wed, 06 Sep 2017 14:58:48 +0200 Johannes Berg [off-list ref] wrote:
+void __ieee80211_start_rx_ba_session(struct sta_info *sta,
+ u8 dialog_token, u16 timeout,
+ u16 start_seq_num, u16 ba_policy, u16 tid,
+ u16 buf_size, bool tx, bool auto_seq)
+{
+ mutex_lock(&sta->ampdu_mlme.mtx);
+ ___ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
+ start_seq_num, ba_policy, tid,
+ buf_size, tx, auto_seq);
+ mutex_unlock(&sta->ampdu_mlme.mtx);
+}
+Sorry for the extended bothering :) but here, you're extending quite a bit the scope of the lock also when__ieee80211_start_rx_ba_session() is called by ieee80211_process_addba_request(). No idea what the hit can be, but we can't safely assume it's nothing either. What about simply introducing a 'ampdu_mlme_lock_held' argument instead? Something like:
diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
index 2b36eff5d97e..35a9eff1ec66 100644
--- a/net/mac80211/agg-rx.c
+++ b/net/mac80211/agg-rx.c@@ -248,7 +248,8 @@ static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *d void __ieee80211_start_rx_ba_session(struct sta_info *sta, u8 dialog_token, u16 timeout, u16 start_seq_num, u16 ba_policy, u16 tid, - u16 buf_size, bool tx, bool auto_seq) + u16 buf_size, bool tx, bool auto_seq, + bool ampdu_mlme_lock_held) { struct ieee80211_local *local = sta->sdata->local; struct tid_ampdu_rx *tid_agg_rx;
@@ -311,7 +312,8 @@ void __ieee80211_start_rx_ba_session(struct sta_info *sta, buf_size, sta->sta.addr); /* examine state machine */ - mutex_lock(&sta->ampdu_mlme.mtx); + if (!ampdu_mlme_lock_held) + mutex_lock(&sta->ampdu_mlme.mtx); if (test_bit(tid, sta->ampdu_mlme.agg_session_valid)) { if (sta->ampdu_mlme.tid_rx_token[tid] == dialog_token) {
@@ -415,7 +417,8 @@ void __ieee80211_start_rx_ba_session(struct sta_info *sta, __clear_bit(tid, sta->ampdu_mlme.unexpected_agg); sta->ampdu_mlme.tid_rx_token[tid] = dialog_token; } - mutex_unlock(&sta->ampdu_mlme.mtx); + if (!ampdu_mlme_lock_held) + mutex_unlock(&sta->ampdu_mlme.mtx); end_no_lock: if (tx)
@@ -445,7 +448,7 @@ void ieee80211_process_addba_request(struct ieee80211_local *local, __ieee80211_start_rx_ba_session(sta, dialog_token, timeout, start_seq_num, ba_policy, tid, - buf_size, true, false); + buf_size, true, false, false); } void ieee80211_manage_rx_ba_offl(struct ieee80211_vif *vif,
diff --git a/net/mac80211/ht.c b/net/mac80211/ht.c
index c92df492e898..59ba67e8942f 100644
--- a/net/mac80211/ht.c
+++ b/net/mac80211/ht.c@@ -335,7 +335,7 @@ void ieee80211_ba_session_work(struct work_struct *work) sta->ampdu_mlme.tid_rx_manage_offl)) __ieee80211_start_rx_ba_session(sta, 0, 0, 0, 1, tid, IEEE80211_MAX_AMPDU_BUF, - false, true); + false, true, true); if (test_and_clear_bit(tid + IEEE80211_NUM_TIDS, sta->ampdu_mlme.tid_rx_manage_offl))
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 2197c62a0a6e..5d494ac65853 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h@@ -1759,7 +1759,8 @@ void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid, void __ieee80211_start_rx_ba_session(struct sta_info *sta, u8 dialog_token, u16 timeout, u16 start_seq_num, u16 ba_policy, u16 tid, - u16 buf_size, bool tx, bool auto_seq); + u16 buf_size, bool tx, bool auto_seq, + bool ampdu_mlme_lock_held); void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta, enum ieee80211_agg_stop_reason reason); void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
--
Stefano