ia64/linux-2.6.18-xen.hg

view drivers/bluetooth/hci_uart.h @ 897:329ea0ccb344

balloon: try harder to balloon up under memory pressure.

Currently if the balloon driver is unable to increase the guest's
reservation it assumes the failure was due to reaching its full
allocation, gives up on the ballooning operation and records the limit
it reached as the "hard limit". The driver will not try again until
the target is set again (even to the same value).

However it is possible that ballooning has in fact failed due to
memory pressure in the host and therefore it is desirable to keep
attempting to reach the target in case memory becomes available. The
most likely scenario is that some guests are ballooning down while
others are ballooning up and therefore there is temporary memory
pressure while things stabilise. You would not expect a well behaved
toolstack to ask a domain to balloon to more than its allocation nor
would you expect it to deliberately over-commit memory by setting
balloon targets which exceed the total host memory.

This patch drops the concept of a hard limit and causes the balloon
driver to retry increasing the reservation on a timer in the same
manner as when decreasing the reservation.

Also if we partially succeed in increasing the reservation
(i.e. receive less pages than we asked for) then we may as well keep
those pages rather than returning them to Xen.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Fri Jun 05 14:01:20 2009 +0100 (2009-06-05)
parents 831230e53067
children
line source
1 /*
2 *
3 * Bluetooth HCI UART driver
4 *
5 * Copyright (C) 2000-2001 Qualcomm Incorporated
6 * Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
7 * Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>
8 *
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 *
24 */
26 #ifndef N_HCI
27 #define N_HCI 15
28 #endif
30 /* Ioctls */
31 #define HCIUARTSETPROTO _IOW('U', 200, int)
32 #define HCIUARTGETPROTO _IOR('U', 201, int)
34 /* UART protocols */
35 #define HCI_UART_MAX_PROTO 4
37 #define HCI_UART_H4 0
38 #define HCI_UART_BCSP 1
39 #define HCI_UART_3WIRE 2
40 #define HCI_UART_H4DS 3
42 struct hci_uart;
44 struct hci_uart_proto {
45 unsigned int id;
46 int (*open)(struct hci_uart *hu);
47 int (*close)(struct hci_uart *hu);
48 int (*flush)(struct hci_uart *hu);
49 int (*recv)(struct hci_uart *hu, void *data, int len);
50 int (*enqueue)(struct hci_uart *hu, struct sk_buff *skb);
51 struct sk_buff *(*dequeue)(struct hci_uart *hu);
52 };
54 struct hci_uart {
55 struct tty_struct *tty;
56 struct hci_dev *hdev;
57 unsigned long flags;
59 struct hci_uart_proto *proto;
60 void *priv;
62 struct sk_buff *tx_skb;
63 unsigned long tx_state;
64 spinlock_t rx_lock;
65 };
67 /* HCI_UART flag bits */
68 #define HCI_UART_PROTO_SET 0
70 /* TX states */
71 #define HCI_UART_SENDING 1
72 #define HCI_UART_TX_WAKEUP 2
74 int hci_uart_register_proto(struct hci_uart_proto *p);
75 int hci_uart_unregister_proto(struct hci_uart_proto *p);
76 int hci_uart_tx_wakeup(struct hci_uart *hu);
78 #ifdef CONFIG_BT_HCIUART_H4
79 int h4_init(void);
80 int h4_deinit(void);
81 #endif
83 #ifdef CONFIG_BT_HCIUART_BCSP
84 int bcsp_init(void);
85 int bcsp_deinit(void);
86 #endif