ia64/linux-2.6.18-xen.hg

view drivers/net/chelsio/cphy.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 * File: cphy.h *
4 * $Revision: 1.7 $ *
5 * $Date: 2005/06/21 18:29:47 $ *
6 * Description: *
7 * part of the Chelsio 10Gb Ethernet Driver. *
8 * *
9 * This program is free software; you can redistribute it and/or modify *
10 * it under the terms of the GNU General Public License, version 2, as *
11 * published by the Free Software Foundation. *
12 * *
13 * You should have received a copy of the GNU General Public License along *
14 * with this program; if not, write to the Free Software Foundation, Inc., *
15 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
16 * *
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED *
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF *
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. *
20 * *
21 * http://www.chelsio.com *
22 * *
23 * Copyright (c) 2003 - 2005 Chelsio Communications, Inc. *
24 * All rights reserved. *
25 * *
26 * Maintainers: maintainers@chelsio.com *
27 * *
28 * Authors: Dimitrios Michailidis <dm@chelsio.com> *
29 * Tina Yang <tainay@chelsio.com> *
30 * Felix Marti <felix@chelsio.com> *
31 * Scott Bardone <sbardone@chelsio.com> *
32 * Kurt Ottaway <kottaway@chelsio.com> *
33 * Frank DiMambro <frank@chelsio.com> *
34 * *
35 * History: *
36 * *
37 ****************************************************************************/
39 #ifndef _CXGB_CPHY_H_
40 #define _CXGB_CPHY_H_
42 #include "common.h"
44 struct mdio_ops {
45 void (*init)(adapter_t *adapter, const struct board_info *bi);
46 int (*read)(adapter_t *adapter, int phy_addr, int mmd_addr,
47 int reg_addr, unsigned int *val);
48 int (*write)(adapter_t *adapter, int phy_addr, int mmd_addr,
49 int reg_addr, unsigned int val);
50 };
52 /* PHY interrupt types */
53 enum {
54 cphy_cause_link_change = 0x1,
55 cphy_cause_error = 0x2
56 };
58 struct cphy;
60 /* PHY operations */
61 struct cphy_ops {
62 void (*destroy)(struct cphy *);
63 int (*reset)(struct cphy *, int wait);
65 int (*interrupt_enable)(struct cphy *);
66 int (*interrupt_disable)(struct cphy *);
67 int (*interrupt_clear)(struct cphy *);
68 int (*interrupt_handler)(struct cphy *);
70 int (*autoneg_enable)(struct cphy *);
71 int (*autoneg_disable)(struct cphy *);
72 int (*autoneg_restart)(struct cphy *);
74 int (*advertise)(struct cphy *phy, unsigned int advertise_map);
75 int (*set_loopback)(struct cphy *, int on);
76 int (*set_speed_duplex)(struct cphy *phy, int speed, int duplex);
77 int (*get_link_status)(struct cphy *phy, int *link_ok, int *speed,
78 int *duplex, int *fc);
79 };
81 /* A PHY instance */
82 struct cphy {
83 int addr; /* PHY address */
84 adapter_t *adapter; /* associated adapter */
85 struct cphy_ops *ops; /* PHY operations */
86 int (*mdio_read)(adapter_t *adapter, int phy_addr, int mmd_addr,
87 int reg_addr, unsigned int *val);
88 int (*mdio_write)(adapter_t *adapter, int phy_addr, int mmd_addr,
89 int reg_addr, unsigned int val);
90 struct cphy_instance *instance;
91 };
93 /* Convenience MDIO read/write wrappers */
94 static inline int mdio_read(struct cphy *cphy, int mmd, int reg,
95 unsigned int *valp)
96 {
97 return cphy->mdio_read(cphy->adapter, cphy->addr, mmd, reg, valp);
98 }
100 static inline int mdio_write(struct cphy *cphy, int mmd, int reg,
101 unsigned int val)
102 {
103 return cphy->mdio_write(cphy->adapter, cphy->addr, mmd, reg, val);
104 }
106 static inline int simple_mdio_read(struct cphy *cphy, int reg,
107 unsigned int *valp)
108 {
109 return mdio_read(cphy, 0, reg, valp);
110 }
112 static inline int simple_mdio_write(struct cphy *cphy, int reg,
113 unsigned int val)
114 {
115 return mdio_write(cphy, 0, reg, val);
116 }
118 /* Convenience initializer */
119 static inline void cphy_init(struct cphy *phy, adapter_t *adapter,
120 int phy_addr, struct cphy_ops *phy_ops,
121 struct mdio_ops *mdio_ops)
122 {
123 phy->adapter = adapter;
124 phy->addr = phy_addr;
125 phy->ops = phy_ops;
126 if (mdio_ops) {
127 phy->mdio_read = mdio_ops->read;
128 phy->mdio_write = mdio_ops->write;
129 }
130 }
132 /* Operations of the PHY-instance factory */
133 struct gphy {
134 /* Construct a PHY instance with the given PHY address */
135 struct cphy *(*create)(adapter_t *adapter, int phy_addr,
136 struct mdio_ops *mdio_ops);
138 /*
139 * Reset the PHY chip. This resets the whole PHY chip, not individual
140 * ports.
141 */
142 int (*reset)(adapter_t *adapter);
143 };
145 extern struct gphy t1_mv88x201x_ops;
146 extern struct gphy t1_dummy_phy_ops;
148 #endif /* _CXGB_CPHY_H_ */