Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 1 | /* drivers/misc/lowmemorykiller.c |
| 2 | * |
| 3 | * The lowmemorykiller driver lets user-space specify a set of memory thresholds |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 4 | * where processes with a range of oom_score_adj values will get killed. Specify |
| 5 | * the minimum oom_score_adj values in |
| 6 | * /sys/module/lowmemorykiller/parameters/adj and the number of free pages in |
| 7 | * /sys/module/lowmemorykiller/parameters/minfree. Both files take a comma |
| 8 | * separated list of numbers in ascending order. |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 9 | * |
| 10 | * For example, write "0,8" to /sys/module/lowmemorykiller/parameters/adj and |
Marco Navarra | 3bf5d65 | 2011-12-22 13:28:23 +0100 | [diff] [blame] | 11 | * "1024,4096" to /sys/module/lowmemorykiller/parameters/minfree to kill |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 12 | * processes with a oom_score_adj value of 8 or higher when the free memory |
| 13 | * drops below 4096 pages and kill processes with a oom_score_adj value of 0 or |
| 14 | * higher when the free memory drops below 1024 pages. |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 15 | * |
| 16 | * The driver considers memory used for caches to be free, but if a large |
| 17 | * percentage of the cached memory is locked this can be very inaccurate |
| 18 | * and processes may not get killed until the normal oom killer is triggered. |
| 19 | * |
| 20 | * Copyright (C) 2007-2008 Google, Inc. |
| 21 | * |
| 22 | * This software is licensed under the terms of the GNU General Public |
| 23 | * License version 2, as published by the Free Software Foundation, and |
| 24 | * may be copied, distributed, and modified under those terms. |
| 25 | * |
| 26 | * This program is distributed in the hope that it will be useful, |
| 27 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 28 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 29 | * GNU General Public License for more details. |
| 30 | * |
| 31 | */ |
| 32 | |
| 33 | #include <linux/module.h> |
| 34 | #include <linux/kernel.h> |
| 35 | #include <linux/mm.h> |
| 36 | #include <linux/oom.h> |
| 37 | #include <linux/sched.h> |
Anton Vorontsov | 294b271 | 2012-02-06 20:29:41 +0400 | [diff] [blame] | 38 | #include <linux/rcupdate.h> |
San Mehat | 4755b72 | 2010-05-05 11:38:42 -0700 | [diff] [blame] | 39 | #include <linux/profile.h> |
| 40 | #include <linux/notifier.h> |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 41 | |
| 42 | static uint32_t lowmem_debug_level = 2; |
| 43 | static int lowmem_adj[6] = { |
| 44 | 0, |
| 45 | 1, |
| 46 | 6, |
| 47 | 12, |
| 48 | }; |
| 49 | static int lowmem_adj_size = 4; |
Greg Kroah-Hartman | 624b225 | 2012-03-07 13:21:23 -0800 | [diff] [blame] | 50 | static int lowmem_minfree[6] = { |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 51 | 3 * 512, /* 6MB */ |
| 52 | 2 * 1024, /* 8MB */ |
| 53 | 4 * 1024, /* 16MB */ |
| 54 | 16 * 1024, /* 64MB */ |
| 55 | }; |
| 56 | static int lowmem_minfree_size = 4; |
| 57 | |
Arve Hjønnevåg | e5d7965 | 2012-01-13 22:21:25 +0400 | [diff] [blame] | 58 | static unsigned long lowmem_deathpending_timeout; |
San Mehat | 4755b72 | 2010-05-05 11:38:42 -0700 | [diff] [blame] | 59 | |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 60 | #define lowmem_print(level, x...) \ |
| 61 | do { \ |
| 62 | if (lowmem_debug_level >= (level)) \ |
| 63 | printk(x); \ |
| 64 | } while (0) |
| 65 | |
Colin Cross | cae9bf1 | 2011-06-22 16:05:47 -0700 | [diff] [blame] | 66 | static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc) |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 67 | { |
Anton Vorontsov | 9567000 | 2012-02-06 20:29:47 +0400 | [diff] [blame] | 68 | struct task_struct *tsk; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 69 | struct task_struct *selected = NULL; |
| 70 | int rem = 0; |
| 71 | int tasksize; |
| 72 | int i; |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 73 | int min_score_adj = OOM_SCORE_ADJ_MAX + 1; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 74 | int selected_tasksize = 0; |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 75 | int selected_oom_score_adj; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 76 | int array_size = ARRAY_SIZE(lowmem_adj); |
| 77 | int other_free = global_page_state(NR_FREE_PAGES); |
Arve Hjønnevåg | 71b2c82 | 2010-11-23 17:29:04 -0800 | [diff] [blame] | 78 | int other_file = global_page_state(NR_FILE_PAGES) - |
| 79 | global_page_state(NR_SHMEM); |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 80 | |
| 81 | if (lowmem_adj_size < array_size) |
| 82 | array_size = lowmem_adj_size; |
| 83 | if (lowmem_minfree_size < array_size) |
| 84 | array_size = lowmem_minfree_size; |
| 85 | for (i = 0; i < array_size; i++) { |
| 86 | if (other_free < lowmem_minfree[i] && |
| 87 | other_file < lowmem_minfree[i]) { |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 88 | min_score_adj = lowmem_adj[i]; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 89 | break; |
| 90 | } |
| 91 | } |
Colin Cross | cae9bf1 | 2011-06-22 16:05:47 -0700 | [diff] [blame] | 92 | if (sc->nr_to_scan > 0) |
| 93 | lowmem_print(3, "lowmem_shrink %lu, %x, ofree %d %d, ma %d\n", |
Marco Navarra | 3bf5d65 | 2011-12-22 13:28:23 +0100 | [diff] [blame] | 94 | sc->nr_to_scan, sc->gfp_mask, other_free, |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 95 | other_file, min_score_adj); |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 96 | rem = global_page_state(NR_ACTIVE_ANON) + |
| 97 | global_page_state(NR_ACTIVE_FILE) + |
| 98 | global_page_state(NR_INACTIVE_ANON) + |
| 99 | global_page_state(NR_INACTIVE_FILE); |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 100 | if (sc->nr_to_scan <= 0 || min_score_adj == OOM_SCORE_ADJ_MAX + 1) { |
Colin Cross | cae9bf1 | 2011-06-22 16:05:47 -0700 | [diff] [blame] | 101 | lowmem_print(5, "lowmem_shrink %lu, %x, return %d\n", |
| 102 | sc->nr_to_scan, sc->gfp_mask, rem); |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 103 | return rem; |
| 104 | } |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 105 | selected_oom_score_adj = min_score_adj; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 106 | |
Anton Vorontsov | 294b271 | 2012-02-06 20:29:41 +0400 | [diff] [blame] | 107 | rcu_read_lock(); |
Anton Vorontsov | 9567000 | 2012-02-06 20:29:47 +0400 | [diff] [blame] | 108 | for_each_process(tsk) { |
| 109 | struct task_struct *p; |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 110 | int oom_score_adj; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 111 | |
Anton Vorontsov | 9823ec9 | 2012-02-06 20:30:01 +0400 | [diff] [blame] | 112 | if (tsk->flags & PF_KTHREAD) |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 113 | continue; |
Anton Vorontsov | 9823ec9 | 2012-02-06 20:30:01 +0400 | [diff] [blame] | 114 | |
Anton Vorontsov | 9567000 | 2012-02-06 20:29:47 +0400 | [diff] [blame] | 115 | p = find_lock_task_mm(tsk); |
| 116 | if (!p) |
| 117 | continue; |
| 118 | |
David Rientjes | 83dbbdb | 2012-04-09 16:56:18 -0700 | [diff] [blame] | 119 | if (test_tsk_thread_flag(p, TIF_MEMDIE) && |
| 120 | time_before_eq(jiffies, lowmem_deathpending_timeout)) { |
| 121 | task_unlock(p); |
| 122 | rcu_read_unlock(); |
| 123 | return 0; |
| 124 | } |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 125 | oom_score_adj = p->signal->oom_score_adj; |
| 126 | if (oom_score_adj < min_score_adj) { |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 127 | task_unlock(p); |
| 128 | continue; |
| 129 | } |
Anton Vorontsov | 9567000 | 2012-02-06 20:29:47 +0400 | [diff] [blame] | 130 | tasksize = get_mm_rss(p->mm); |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 131 | task_unlock(p); |
| 132 | if (tasksize <= 0) |
| 133 | continue; |
| 134 | if (selected) { |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 135 | if (oom_score_adj < selected_oom_score_adj) |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 136 | continue; |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 137 | if (oom_score_adj == selected_oom_score_adj && |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 138 | tasksize <= selected_tasksize) |
| 139 | continue; |
| 140 | } |
| 141 | selected = p; |
| 142 | selected_tasksize = tasksize; |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 143 | selected_oom_score_adj = oom_score_adj; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 144 | lowmem_print(2, "select %d (%s), adj %d, size %d, to kill\n", |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 145 | p->pid, p->comm, oom_score_adj, tasksize); |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 146 | } |
| 147 | if (selected) { |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 148 | lowmem_print(1, "send sigkill to %d (%s), adj %d, size %d\n", |
| 149 | selected->pid, selected->comm, |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 150 | selected_oom_score_adj, selected_tasksize); |
Arve Hjønnevåg | e5d7965 | 2012-01-13 22:21:25 +0400 | [diff] [blame] | 151 | lowmem_deathpending_timeout = jiffies + HZ; |
Anton Vorontsov | 294b271 | 2012-02-06 20:29:41 +0400 | [diff] [blame] | 152 | send_sig(SIGKILL, selected, 0); |
David Rientjes | 83dbbdb | 2012-04-09 16:56:18 -0700 | [diff] [blame] | 153 | set_tsk_thread_flag(selected, TIF_MEMDIE); |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 154 | rem -= selected_tasksize; |
| 155 | } |
Colin Cross | cae9bf1 | 2011-06-22 16:05:47 -0700 | [diff] [blame] | 156 | lowmem_print(4, "lowmem_shrink %lu, %x, return %d\n", |
| 157 | sc->nr_to_scan, sc->gfp_mask, rem); |
Anton Vorontsov | 294b271 | 2012-02-06 20:29:41 +0400 | [diff] [blame] | 158 | rcu_read_unlock(); |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 159 | return rem; |
| 160 | } |
| 161 | |
| 162 | static struct shrinker lowmem_shrinker = { |
| 163 | .shrink = lowmem_shrink, |
| 164 | .seeks = DEFAULT_SEEKS * 16 |
| 165 | }; |
| 166 | |
| 167 | static int __init lowmem_init(void) |
| 168 | { |
| 169 | register_shrinker(&lowmem_shrinker); |
| 170 | return 0; |
| 171 | } |
| 172 | |
| 173 | static void __exit lowmem_exit(void) |
| 174 | { |
| 175 | unregister_shrinker(&lowmem_shrinker); |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 176 | } |
| 177 | |
| 178 | module_param_named(cost, lowmem_shrinker.seeks, int, S_IRUGO | S_IWUSR); |
| 179 | module_param_array_named(adj, lowmem_adj, int, &lowmem_adj_size, |
| 180 | S_IRUGO | S_IWUSR); |
| 181 | module_param_array_named(minfree, lowmem_minfree, uint, &lowmem_minfree_size, |
| 182 | S_IRUGO | S_IWUSR); |
| 183 | module_param_named(debug_level, lowmem_debug_level, uint, S_IRUGO | S_IWUSR); |
| 184 | |
| 185 | module_init(lowmem_init); |
| 186 | module_exit(lowmem_exit); |
| 187 | |
| 188 | MODULE_LICENSE("GPL"); |
| 189 | |