1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3 * CDDL HEADER START
4 *
5 * The contents of this file are subject to the terms of the
6 * Common Development and Distribution License (the "License").
7 * You may not use this file except in compliance with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or https://opensource.org/licenses/CDDL-1.0.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Copyright (c) 2018, Joyent, Inc.
25 * Copyright (c) 2011, 2019 by Delphix. All rights reserved.
26 * Copyright (c) 2014 by Saso Kiselkov. All rights reserved.
27 * Copyright 2017 Nexenta Systems, Inc. All rights reserved.
28 */
29
30 #include <sys/zfs_context.h>
31 #include <sys/arc_impl.h>
32
33 /*
34 * Return a default max arc size based on the amount of physical memory.
35 * This may be overridden by tuning the zfs_arc_max module parameter.
36 */
37 uint64_t
arc_default_max(uint64_t min,uint64_t allmem)38 arc_default_max(uint64_t min, uint64_t allmem)
39 {
40 uint64_t size;
41
42 if (allmem >= 1 << 30)
43 size = allmem - (1 << 30);
44 else
45 size = min;
46 return (MAX(allmem * 5 / 8, size));
47 }
48
49 int64_t
arc_available_memory(void)50 arc_available_memory(void)
51 {
52 int64_t lowest = INT64_MAX;
53
54 /* Every 100 calls, free a small amount */
55 if (random_in_range(100) == 0)
56 lowest = -1024;
57
58 return (lowest);
59 }
60
61 int
arc_memory_throttle(spa_t * spa,uint64_t reserve,uint64_t txg)62 arc_memory_throttle(spa_t *spa, uint64_t reserve, uint64_t txg)
63 {
64 (void) spa, (void) reserve, (void) txg;
65 return (0);
66 }
67
68 uint64_t
arc_all_memory(void)69 arc_all_memory(void)
70 {
71 return (ptob(physmem) / 2);
72 }
73
74 uint64_t
arc_free_memory(void)75 arc_free_memory(void)
76 {
77 return (random_in_range(arc_all_memory() * 20 / 100));
78 }
79
80 void
arc_register_hotplug(void)81 arc_register_hotplug(void)
82 {
83 }
84
85 void
arc_unregister_hotplug(void)86 arc_unregister_hotplug(void)
87 {
88 }
89