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 | |
Dmitry Voytik | 6b83f91 | 2013-03-16 11:37:26 +0400 | [diff] [blame] | 33 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 34 | |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 35 | #include <linux/module.h> |
| 36 | #include <linux/kernel.h> |
| 37 | #include <linux/mm.h> |
| 38 | #include <linux/oom.h> |
| 39 | #include <linux/sched.h> |
Arve Hjønnevåg | eeb0f4f | 2013-02-26 22:07:35 -0800 | [diff] [blame] | 40 | #include <linux/swap.h> |
Anton Vorontsov | 294b271 | 2012-02-06 20:29:41 +0400 | [diff] [blame] | 41 | #include <linux/rcupdate.h> |
San Mehat | 4755b72 | 2010-05-05 11:38:42 -0700 | [diff] [blame] | 42 | #include <linux/profile.h> |
| 43 | #include <linux/notifier.h> |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 44 | |
Arve Hjønnevåg | 99150f6 | 2013-02-26 22:07:36 -0800 | [diff] [blame] | 45 | static uint32_t lowmem_debug_level = 1; |
David Rientjes | a9c58b90 | 2012-12-11 16:02:54 -0800 | [diff] [blame] | 46 | static short lowmem_adj[6] = { |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 47 | 0, |
| 48 | 1, |
| 49 | 6, |
| 50 | 12, |
| 51 | }; |
| 52 | static int lowmem_adj_size = 4; |
Greg Kroah-Hartman | 624b225 | 2012-03-07 13:21:23 -0800 | [diff] [blame] | 53 | static int lowmem_minfree[6] = { |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 54 | 3 * 512, /* 6MB */ |
| 55 | 2 * 1024, /* 8MB */ |
| 56 | 4 * 1024, /* 16MB */ |
| 57 | 16 * 1024, /* 64MB */ |
| 58 | }; |
| 59 | static int lowmem_minfree_size = 4; |
| 60 | |
Arve Hjønnevåg | e5d7965 | 2012-01-13 22:21:25 +0400 | [diff] [blame] | 61 | static unsigned long lowmem_deathpending_timeout; |
San Mehat | 4755b72 | 2010-05-05 11:38:42 -0700 | [diff] [blame] | 62 | |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 63 | #define lowmem_print(level, x...) \ |
| 64 | do { \ |
| 65 | if (lowmem_debug_level >= (level)) \ |
Dmitry Voytik | 6b83f91 | 2013-03-16 11:37:26 +0400 | [diff] [blame] | 66 | pr_info(x); \ |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 67 | } while (0) |
| 68 | |
Dave Chinner | 7dc19d5 | 2013-08-28 10:18:11 +1000 | [diff] [blame] | 69 | static unsigned long lowmem_count(struct shrinker *s, |
| 70 | struct shrink_control *sc) |
| 71 | { |
| 72 | return global_page_state(NR_ACTIVE_ANON) + |
| 73 | global_page_state(NR_ACTIVE_FILE) + |
| 74 | global_page_state(NR_INACTIVE_ANON) + |
| 75 | global_page_state(NR_INACTIVE_FILE); |
| 76 | } |
| 77 | |
| 78 | static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc) |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 79 | { |
Anton Vorontsov | 9567000 | 2012-02-06 20:29:47 +0400 | [diff] [blame] | 80 | struct task_struct *tsk; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 81 | struct task_struct *selected = NULL; |
Dave Chinner | 7dc19d5 | 2013-08-28 10:18:11 +1000 | [diff] [blame] | 82 | unsigned long rem = 0; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 83 | int tasksize; |
| 84 | int i; |
David Rientjes | a9c58b90 | 2012-12-11 16:02:54 -0800 | [diff] [blame] | 85 | short min_score_adj = OOM_SCORE_ADJ_MAX + 1; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 86 | int selected_tasksize = 0; |
David Rientjes | a9c58b90 | 2012-12-11 16:02:54 -0800 | [diff] [blame] | 87 | short selected_oom_score_adj; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 88 | int array_size = ARRAY_SIZE(lowmem_adj); |
Arve Hjønnevåg | eeb0f4f | 2013-02-26 22:07:35 -0800 | [diff] [blame] | 89 | int other_free = global_page_state(NR_FREE_PAGES) - totalreserve_pages; |
Arve Hjønnevåg | 71b2c82 | 2010-11-23 17:29:04 -0800 | [diff] [blame] | 90 | int other_file = global_page_state(NR_FILE_PAGES) - |
Vinayak Menon | 058dbde | 2014-02-27 00:36:22 +0530 | [diff] [blame^] | 91 | global_page_state(NR_SHMEM) - |
| 92 | total_swapcache_pages(); |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 93 | |
| 94 | if (lowmem_adj_size < array_size) |
| 95 | array_size = lowmem_adj_size; |
| 96 | if (lowmem_minfree_size < array_size) |
| 97 | array_size = lowmem_minfree_size; |
| 98 | for (i = 0; i < array_size; i++) { |
| 99 | if (other_free < lowmem_minfree[i] && |
| 100 | other_file < lowmem_minfree[i]) { |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 101 | min_score_adj = lowmem_adj[i]; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 102 | break; |
| 103 | } |
| 104 | } |
Dave Chinner | 7dc19d5 | 2013-08-28 10:18:11 +1000 | [diff] [blame] | 105 | |
| 106 | lowmem_print(3, "lowmem_scan %lu, %x, ofree %d %d, ma %hd\n", |
| 107 | sc->nr_to_scan, sc->gfp_mask, other_free, |
| 108 | other_file, min_score_adj); |
| 109 | |
| 110 | if (min_score_adj == OOM_SCORE_ADJ_MAX + 1) { |
| 111 | lowmem_print(5, "lowmem_scan %lu, %x, return 0\n", |
| 112 | sc->nr_to_scan, sc->gfp_mask); |
| 113 | return 0; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 114 | } |
Dave Chinner | 7dc19d5 | 2013-08-28 10:18:11 +1000 | [diff] [blame] | 115 | |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 116 | selected_oom_score_adj = min_score_adj; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 117 | |
Anton Vorontsov | 294b271 | 2012-02-06 20:29:41 +0400 | [diff] [blame] | 118 | rcu_read_lock(); |
Anton Vorontsov | 9567000 | 2012-02-06 20:29:47 +0400 | [diff] [blame] | 119 | for_each_process(tsk) { |
| 120 | struct task_struct *p; |
David Rientjes | a9c58b90 | 2012-12-11 16:02:54 -0800 | [diff] [blame] | 121 | short oom_score_adj; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 122 | |
Anton Vorontsov | 9823ec9 | 2012-02-06 20:30:01 +0400 | [diff] [blame] | 123 | if (tsk->flags & PF_KTHREAD) |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 124 | continue; |
Anton Vorontsov | 9823ec9 | 2012-02-06 20:30:01 +0400 | [diff] [blame] | 125 | |
Anton Vorontsov | 9567000 | 2012-02-06 20:29:47 +0400 | [diff] [blame] | 126 | p = find_lock_task_mm(tsk); |
| 127 | if (!p) |
| 128 | continue; |
| 129 | |
David Rientjes | 83dbbdb | 2012-04-09 16:56:18 -0700 | [diff] [blame] | 130 | if (test_tsk_thread_flag(p, TIF_MEMDIE) && |
| 131 | time_before_eq(jiffies, lowmem_deathpending_timeout)) { |
| 132 | task_unlock(p); |
| 133 | rcu_read_unlock(); |
| 134 | return 0; |
| 135 | } |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 136 | oom_score_adj = p->signal->oom_score_adj; |
| 137 | if (oom_score_adj < min_score_adj) { |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 138 | task_unlock(p); |
| 139 | continue; |
| 140 | } |
Anton Vorontsov | 9567000 | 2012-02-06 20:29:47 +0400 | [diff] [blame] | 141 | tasksize = get_mm_rss(p->mm); |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 142 | task_unlock(p); |
| 143 | if (tasksize <= 0) |
| 144 | continue; |
| 145 | if (selected) { |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 146 | if (oom_score_adj < selected_oom_score_adj) |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 147 | continue; |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 148 | if (oom_score_adj == selected_oom_score_adj && |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 149 | tasksize <= selected_tasksize) |
| 150 | continue; |
| 151 | } |
| 152 | selected = p; |
| 153 | selected_tasksize = tasksize; |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 154 | selected_oom_score_adj = oom_score_adj; |
David Rientjes | a9c58b90 | 2012-12-11 16:02:54 -0800 | [diff] [blame] | 155 | lowmem_print(2, "select %d (%s), adj %hd, size %d, to kill\n", |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 156 | p->pid, p->comm, oom_score_adj, tasksize); |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 157 | } |
| 158 | if (selected) { |
David Rientjes | a9c58b90 | 2012-12-11 16:02:54 -0800 | [diff] [blame] | 159 | lowmem_print(1, "send sigkill to %d (%s), adj %hd, size %d\n", |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 160 | selected->pid, selected->comm, |
David Rientjes | 940f77b | 2012-02-13 19:28:49 -0800 | [diff] [blame] | 161 | selected_oom_score_adj, selected_tasksize); |
Arve Hjønnevåg | e5d7965 | 2012-01-13 22:21:25 +0400 | [diff] [blame] | 162 | lowmem_deathpending_timeout = jiffies + HZ; |
David Rientjes | 83dbbdb | 2012-04-09 16:56:18 -0700 | [diff] [blame] | 163 | set_tsk_thread_flag(selected, TIF_MEMDIE); |
Weijie Yang | 6bc2b85 | 2014-02-14 14:03:56 +0800 | [diff] [blame] | 164 | send_sig(SIGKILL, selected, 0); |
Dave Chinner | 7dc19d5 | 2013-08-28 10:18:11 +1000 | [diff] [blame] | 165 | rem += selected_tasksize; |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 166 | } |
Dave Chinner | 7dc19d5 | 2013-08-28 10:18:11 +1000 | [diff] [blame] | 167 | |
| 168 | lowmem_print(4, "lowmem_scan %lu, %x, return %lu\n", |
Colin Cross | cae9bf1 | 2011-06-22 16:05:47 -0700 | [diff] [blame] | 169 | sc->nr_to_scan, sc->gfp_mask, rem); |
Anton Vorontsov | 294b271 | 2012-02-06 20:29:41 +0400 | [diff] [blame] | 170 | rcu_read_unlock(); |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 171 | return rem; |
| 172 | } |
| 173 | |
| 174 | static struct shrinker lowmem_shrinker = { |
Dave Chinner | 7dc19d5 | 2013-08-28 10:18:11 +1000 | [diff] [blame] | 175 | .scan_objects = lowmem_scan, |
| 176 | .count_objects = lowmem_count, |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 177 | .seeks = DEFAULT_SEEKS * 16 |
| 178 | }; |
| 179 | |
| 180 | static int __init lowmem_init(void) |
| 181 | { |
| 182 | register_shrinker(&lowmem_shrinker); |
| 183 | return 0; |
| 184 | } |
| 185 | |
| 186 | static void __exit lowmem_exit(void) |
| 187 | { |
| 188 | unregister_shrinker(&lowmem_shrinker); |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 189 | } |
| 190 | |
| 191 | module_param_named(cost, lowmem_shrinker.seeks, int, S_IRUGO | S_IWUSR); |
David Rientjes | a9c58b90 | 2012-12-11 16:02:54 -0800 | [diff] [blame] | 192 | module_param_array_named(adj, lowmem_adj, short, &lowmem_adj_size, |
Greg Kroah-Hartman | 355b050 | 2011-11-30 20:18:14 +0900 | [diff] [blame] | 193 | S_IRUGO | S_IWUSR); |
| 194 | module_param_array_named(minfree, lowmem_minfree, uint, &lowmem_minfree_size, |
| 195 | S_IRUGO | S_IWUSR); |
| 196 | module_param_named(debug_level, lowmem_debug_level, uint, S_IRUGO | S_IWUSR); |
| 197 | |
| 198 | module_init(lowmem_init); |
| 199 | module_exit(lowmem_exit); |
| 200 | |
| 201 | MODULE_LICENSE("GPL"); |
| 202 | |