Return-Path: From: Luiz Augusto von Dentz To: linux-bluetooth@vger.kernel.org Subject: [RFC 5/5 v3] Bluetooth: recalculate priorities when channels are starving Date: Mon, 12 Sep 2011 20:00:53 +0300 Message-Id: <1315846853-27442-5-git-send-email-luiz.dentz@gmail.com> In-Reply-To: <1315846853-27442-1-git-send-email-luiz.dentz@gmail.com> References: <1315846853-27442-1-git-send-email-luiz.dentz@gmail.com> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: From: Luiz Augusto von Dentz 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 --- net/bluetooth/hci_core.c | 56 +++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 55 insertions(+), 1 deletions(-) diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 821b69b..0fd4fc3 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -2207,6 +2207,53 @@ 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; @@ -2245,6 +2292,9 @@ 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 */ @@ -2298,7 +2348,7 @@ 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); @@ -2314,6 +2364,7 @@ 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))) { while (quote-- && (skb = skb_dequeue(&chan->data_q))) { BT_DBG("chan %p skb %p len %d priority %u", chan, skb, @@ -2332,6 +2383,9 @@ 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) -- 1.7.6.1