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