ia64/linux-2.6.18-xen.hg

view drivers/acpi/utilities/utinit.c @ 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 * Module Name: utinit - Common ACPI subsystem initialization
4 *
5 *****************************************************************************/
7 /*
8 * Copyright (C) 2000 - 2006, R. Byron Moore
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions, and the following disclaimer,
16 * without modification.
17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18 * substantially similar to the "NO WARRANTY" disclaimer below
19 * ("Disclaimer") and any redistribution must be conditioned upon
20 * including a substantially similar Disclaimer requirement for further
21 * binary redistribution.
22 * 3. Neither the names of the above-listed copyright holders nor the names
23 * of any contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * Alternatively, this software may be distributed under the terms of the
27 * GNU General Public License ("GPL") version 2 as published by the Free
28 * Software Foundation.
29 *
30 * NO WARRANTY
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41 * POSSIBILITY OF SUCH DAMAGES.
42 */
44 #include <acpi/acpi.h>
45 #include <acpi/acnamesp.h>
46 #include <acpi/acevents.h>
48 #define _COMPONENT ACPI_UTILITIES
49 ACPI_MODULE_NAME("utinit")
51 /* Local prototypes */
52 static void
53 acpi_ut_fadt_register_error(char *register_name, u32 value, u8 offset);
55 static void acpi_ut_terminate(void);
57 /*******************************************************************************
58 *
59 * FUNCTION: acpi_ut_fadt_register_error
60 *
61 * PARAMETERS: register_name - Pointer to string identifying register
62 * Value - Actual register contents value
63 * Offset - Byte offset in the FADT
64 *
65 * RETURN: AE_BAD_VALUE
66 *
67 * DESCRIPTION: Display failure message
68 *
69 ******************************************************************************/
71 static void
72 acpi_ut_fadt_register_error(char *register_name, u32 value, u8 offset)
73 {
75 ACPI_WARNING((AE_INFO,
76 "Invalid FADT value %s=%X at offset %X FADT=%p",
77 register_name, value, offset, acpi_gbl_FADT));
78 }
80 /******************************************************************************
81 *
82 * FUNCTION: acpi_ut_validate_fadt
83 *
84 * PARAMETERS: None
85 *
86 * RETURN: Status
87 *
88 * DESCRIPTION: Validate various ACPI registers in the FADT
89 *
90 ******************************************************************************/
92 acpi_status acpi_ut_validate_fadt(void)
93 {
95 /*
96 * Verify Fixed ACPI Description Table fields,
97 * but don't abort on any problems, just display error
98 */
99 if (acpi_gbl_FADT->pm1_evt_len < 4) {
100 acpi_ut_fadt_register_error("PM1_EVT_LEN",
101 (u32) acpi_gbl_FADT->pm1_evt_len,
102 ACPI_FADT_OFFSET(pm1_evt_len));
103 }
105 if (!acpi_gbl_FADT->pm1_cnt_len) {
106 acpi_ut_fadt_register_error("PM1_CNT_LEN", 0,
107 ACPI_FADT_OFFSET(pm1_cnt_len));
108 }
110 if (!acpi_gbl_FADT->xpm1a_evt_blk.address) {
111 acpi_ut_fadt_register_error("X_PM1a_EVT_BLK", 0,
112 ACPI_FADT_OFFSET(xpm1a_evt_blk.
113 address));
114 }
116 if (!acpi_gbl_FADT->xpm1a_cnt_blk.address) {
117 acpi_ut_fadt_register_error("X_PM1a_CNT_BLK", 0,
118 ACPI_FADT_OFFSET(xpm1a_cnt_blk.
119 address));
120 }
122 if (!acpi_gbl_FADT->xpm_tmr_blk.address) {
123 acpi_ut_fadt_register_error("X_PM_TMR_BLK", 0,
124 ACPI_FADT_OFFSET(xpm_tmr_blk.
125 address));
126 }
128 if ((acpi_gbl_FADT->xpm2_cnt_blk.address &&
129 !acpi_gbl_FADT->pm2_cnt_len)) {
130 acpi_ut_fadt_register_error("PM2_CNT_LEN",
131 (u32) acpi_gbl_FADT->pm2_cnt_len,
132 ACPI_FADT_OFFSET(pm2_cnt_len));
133 }
135 if (acpi_gbl_FADT->pm_tm_len < 4) {
136 acpi_ut_fadt_register_error("PM_TM_LEN",
137 (u32) acpi_gbl_FADT->pm_tm_len,
138 ACPI_FADT_OFFSET(pm_tm_len));
139 }
141 /* Length of GPE blocks must be a multiple of 2 */
143 if (acpi_gbl_FADT->xgpe0_blk.address &&
144 (acpi_gbl_FADT->gpe0_blk_len & 1)) {
145 acpi_ut_fadt_register_error("(x)GPE0_BLK_LEN",
146 (u32) acpi_gbl_FADT->gpe0_blk_len,
147 ACPI_FADT_OFFSET(gpe0_blk_len));
148 }
150 if (acpi_gbl_FADT->xgpe1_blk.address &&
151 (acpi_gbl_FADT->gpe1_blk_len & 1)) {
152 acpi_ut_fadt_register_error("(x)GPE1_BLK_LEN",
153 (u32) acpi_gbl_FADT->gpe1_blk_len,
154 ACPI_FADT_OFFSET(gpe1_blk_len));
155 }
157 return (AE_OK);
158 }
160 /******************************************************************************
161 *
162 * FUNCTION: acpi_ut_terminate
163 *
164 * PARAMETERS: none
165 *
166 * RETURN: none
167 *
168 * DESCRIPTION: Free global memory
169 *
170 ******************************************************************************/
172 static void acpi_ut_terminate(void)
173 {
174 struct acpi_gpe_block_info *gpe_block;
175 struct acpi_gpe_block_info *next_gpe_block;
176 struct acpi_gpe_xrupt_info *gpe_xrupt_info;
177 struct acpi_gpe_xrupt_info *next_gpe_xrupt_info;
179 ACPI_FUNCTION_TRACE(ut_terminate);
181 /* Free global tables, etc. */
182 /* Free global GPE blocks and related info structures */
184 gpe_xrupt_info = acpi_gbl_gpe_xrupt_list_head;
185 while (gpe_xrupt_info) {
186 gpe_block = gpe_xrupt_info->gpe_block_list_head;
187 while (gpe_block) {
188 next_gpe_block = gpe_block->next;
189 ACPI_FREE(gpe_block->event_info);
190 ACPI_FREE(gpe_block->register_info);
191 ACPI_FREE(gpe_block);
193 gpe_block = next_gpe_block;
194 }
195 next_gpe_xrupt_info = gpe_xrupt_info->next;
196 ACPI_FREE(gpe_xrupt_info);
197 gpe_xrupt_info = next_gpe_xrupt_info;
198 }
200 return_VOID;
201 }
203 /*******************************************************************************
204 *
205 * FUNCTION: acpi_ut_subsystem_shutdown
206 *
207 * PARAMETERS: none
208 *
209 * RETURN: none
210 *
211 * DESCRIPTION: Shutdown the various subsystems. Don't delete the mutex
212 * objects here -- because the AML debugger may be still running.
213 *
214 ******************************************************************************/
216 void acpi_ut_subsystem_shutdown(void)
217 {
219 ACPI_FUNCTION_TRACE(ut_subsystem_shutdown);
221 /* Just exit if subsystem is already shutdown */
223 if (acpi_gbl_shutdown) {
224 ACPI_ERROR((AE_INFO, "ACPI Subsystem is already terminated"));
225 return_VOID;
226 }
228 /* Subsystem appears active, go ahead and shut it down */
230 acpi_gbl_shutdown = TRUE;
231 acpi_gbl_startup_flags = 0;
232 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Shutting down ACPI Subsystem\n"));
234 /* Close the acpi_event Handling */
236 acpi_ev_terminate();
238 /* Close the Namespace */
240 acpi_ns_terminate();
242 /* Close the globals */
244 acpi_ut_terminate();
246 /* Purge the local caches */
248 (void)acpi_ut_delete_caches();
249 return_VOID;
250 }