From 02b20f0bb661829cbd431e5deb2474e909e65cec Mon Sep 17 00:00:00 2001 From: Luiz Augusto von Dentz Date: Wed, 2 Nov 2011 15:52:03 +0200 Subject: Bluetooth: recalculate priorities when channels are starving To avoid starvation the priority is recalculated so that the starving channels are promoted to HCI_PRIO_MAX - 1 (6). HCI_PRIO_MAX (7) is considered special, because it requires CAP_NET_ADMIN capability which can be used to provide more guaranties, so it is not used when promoting. Signed-off-by: Luiz Augusto von Dentz Acked-by: Marcel Holtmann Signed-off-by: Gustavo F. Padovan --- net/bluetooth/hci_core.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 55 insertions(+), 1 deletion(-) (limited to 'net/bluetooth') diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 19e44533fb0..4221fd5b1f4 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -2170,6 +2170,53 @@ static inline struct hci_chan *hci_chan_sent(struct hci_dev *hdev, __u8 type, return chan; } +static void hci_prio_recalculate(struct hci_dev *hdev, __u8 type) +{ + struct hci_conn_hash *h = &hdev->conn_hash; + struct hci_conn *conn; + int num = 0; + + BT_DBG("%s", hdev->name); + + list_for_each_entry(conn, &h->list, list) { + struct hci_chan_hash *ch; + struct hci_chan *chan; + + if (conn->type != type) + continue; + + if (conn->state != BT_CONNECTED && conn->state != BT_CONFIG) + continue; + + num++; + + ch = &conn->chan_hash; + list_for_each_entry(chan, &ch->list, list) { + struct sk_buff *skb; + + if (chan->sent) { + chan->sent = 0; + continue; + } + + if (skb_queue_empty(&chan->data_q)) + continue; + + skb = skb_peek(&chan->data_q); + if (skb->priority >= HCI_PRIO_MAX - 1) + continue; + + skb->priority = HCI_PRIO_MAX - 1; + + BT_DBG("chan %p skb %p promoted to %d", chan, skb, + skb->priority); + } + + if (hci_conn_num(hdev, type) == num) + break; + } +} + static inline void hci_sched_acl(struct hci_dev *hdev) { struct hci_chan *chan; @@ -2215,6 +2262,9 @@ static inline void hci_sched_acl(struct hci_dev *hdev) chan->conn->sent++; } } + + if (cnt != hdev->acl_cnt) + hci_prio_recalculate(hdev, ACL_LINK); } /* Schedule SCO */ @@ -2268,7 +2318,7 @@ static inline void hci_sched_le(struct hci_dev *hdev) { struct hci_chan *chan; struct sk_buff *skb; - int quote, cnt; + int quote, cnt, tmp; BT_DBG("%s", hdev->name); @@ -2284,6 +2334,7 @@ static inline void hci_sched_le(struct hci_dev *hdev) } cnt = hdev->le_pkts ? hdev->le_cnt : hdev->acl_cnt; + tmp = cnt; while (cnt && (chan = hci_chan_sent(hdev, LE_LINK, "e))) { u32 priority = (skb_peek(&chan->data_q))->priority; while (quote-- && (skb = skb_peek(&chan->data_q))) { @@ -2309,6 +2360,9 @@ static inline void hci_sched_le(struct hci_dev *hdev) hdev->le_cnt = cnt; else hdev->acl_cnt = cnt; + + if (cnt != tmp) + hci_prio_recalculate(hdev, LE_LINK); } static void hci_tx_task(unsigned long arg) -- cgit v1.2.3-70-g09d2