| /* drivers/misc/lowmemorykiller.c |
| * |
| * The lowmemorykiller driver lets user-space specify a set of memory thresholds |
| * where processes with a range of oom_score_adj values will get killed. Specify |
| * the minimum oom_score_adj values in |
| * /sys/module/lowmemorykiller/parameters/adj and the number of free pages in |
| * /sys/module/lowmemorykiller/parameters/minfree. Both files take a comma |
| * separated list of numbers in ascending order. |
| * |
| * For example, write "0,8" to /sys/module/lowmemorykiller/parameters/adj and |
| * "1024,4096" to /sys/module/lowmemorykiller/parameters/minfree to kill |
| * processes with a oom_score_adj value of 8 or higher when the free memory |
| * drops below 4096 pages and kill processes with a oom_score_adj value of 0 or |
| * higher when the free memory drops below 1024 pages. |
| * |
| * The driver considers memory used for caches to be free, but if a large |
| * percentage of the cached memory is locked this can be very inaccurate |
| * and processes may not get killed until the normal oom killer is triggered. |
| * |
| * Copyright (C) 2007-2008 Google, Inc. |
| * |
| * This software is licensed under the terms of the GNU General Public |
| * License version 2, as published by the Free Software Foundation, and |
| * may be copied, distributed, and modified under those terms. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/oom.h> |
| #include <linux/sched.h> |
| #include <linux/rcupdate.h> |
| #include <linux/notifier.h> |
| #include <linux/mutex.h> |
| #include <linux/delay.h> |
| #include <linux/swap.h> |
| |
| #ifdef CONFIG_HIGHMEM |
| #define _ZONE ZONE_HIGHMEM |
| #else |
| #define _ZONE ZONE_NORMAL |
| #endif |
| |
| static uint32_t lowmem_debug_level = 1; |
| static int lowmem_adj[6] = { |
| 0, |
| 1, |
| 6, |
| 12, |
| }; |
| static int lowmem_adj_size = 4; |
| static int lowmem_minfree[6] = { |
| 3 * 512, /* 6MB */ |
| 2 * 1024, /* 8MB */ |
| 4 * 1024, /* 16MB */ |
| 16 * 1024, /* 64MB */ |
| }; |
| static int lowmem_minfree_size = 4; |
| static int lmk_fast_run = 1; |
| |
| static unsigned long lowmem_deathpending_timeout; |
| |
| #define lowmem_print(level, x...) \ |
| do { \ |
| if (lowmem_debug_level >= (level)) \ |
| printk(x); \ |
| } while (0) |
| |
| static int test_task_flag(struct task_struct *p, int flag) |
| { |
| struct task_struct *t = p; |
| |
| do { |
| task_lock(t); |
| if (test_tsk_thread_flag(t, flag)) { |
| task_unlock(t); |
| return 1; |
| } |
| task_unlock(t); |
| } while_each_thread(p, t); |
| |
| return 0; |
| } |
| |
| static DEFINE_MUTEX(scan_mutex); |
| |
| int can_use_cma_pages(gfp_t gfp_mask) |
| { |
| int can_use = 0; |
| int mtype = allocflags_to_migratetype(gfp_mask); |
| int i = 0; |
| int *mtype_fallbacks = get_migratetype_fallbacks(mtype); |
| |
| if (is_migrate_cma(mtype)) { |
| can_use = 1; |
| } else { |
| for (i = 0;; i++) { |
| int fallbacktype = mtype_fallbacks[i]; |
| |
| if (is_migrate_cma(fallbacktype)) { |
| can_use = 1; |
| break; |
| } |
| |
| if (fallbacktype == MIGRATE_RESERVE) |
| break; |
| } |
| } |
| return can_use; |
| } |
| |
| void tune_lmk_zone_param(struct zonelist *zonelist, int classzone_idx, |
| int *other_free, int *other_file, |
| int use_cma_pages) |
| { |
| struct zone *zone; |
| struct zoneref *zoneref; |
| int zone_idx; |
| |
| for_each_zone_zonelist(zone, zoneref, zonelist, MAX_NR_ZONES) { |
| zone_idx = zonelist_zone_idx(zoneref); |
| if (zone_idx == ZONE_MOVABLE) { |
| if (!use_cma_pages) |
| *other_free -= |
| zone_page_state(zone, NR_FREE_CMA_PAGES); |
| continue; |
| } |
| |
| if (zone_idx > classzone_idx) { |
| if (other_free != NULL) |
| *other_free -= zone_page_state(zone, |
| NR_FREE_PAGES); |
| if (other_file != NULL) |
| *other_file -= zone_page_state(zone, |
| NR_FILE_PAGES) |
| - zone_page_state(zone, NR_SHMEM); |
| } else if (zone_idx < classzone_idx) { |
| if (zone_watermark_ok(zone, 0, 0, classzone_idx, 0)) { |
| if (!use_cma_pages) { |
| *other_free -= min( |
| zone->lowmem_reserve[classzone_idx] + |
| zone_page_state( |
| zone, NR_FREE_CMA_PAGES), |
| zone_page_state( |
| zone, NR_FREE_PAGES)); |
| } else { |
| *other_free -= |
| zone->lowmem_reserve[classzone_idx]; |
| } |
| } else { |
| *other_free -= |
| zone_page_state(zone, NR_FREE_PAGES); |
| } |
| } |
| } |
| } |
| |
| void tune_lmk_param(int *other_free, int *other_file, struct shrink_control *sc) |
| { |
| gfp_t gfp_mask; |
| struct zone *preferred_zone; |
| struct zonelist *zonelist; |
| enum zone_type high_zoneidx, classzone_idx; |
| unsigned long balance_gap; |
| int use_cma_pages; |
| |
| gfp_mask = sc->gfp_mask; |
| zonelist = node_zonelist(0, gfp_mask); |
| high_zoneidx = gfp_zone(gfp_mask); |
| first_zones_zonelist(zonelist, high_zoneidx, NULL, &preferred_zone); |
| classzone_idx = zone_idx(preferred_zone); |
| use_cma_pages = can_use_cma_pages(gfp_mask); |
| |
| balance_gap = min(low_wmark_pages(preferred_zone), |
| (preferred_zone->present_pages + |
| KSWAPD_ZONE_BALANCE_GAP_RATIO-1) / |
| KSWAPD_ZONE_BALANCE_GAP_RATIO); |
| |
| if (likely(current_is_kswapd() && zone_watermark_ok(preferred_zone, 0, |
| high_wmark_pages(preferred_zone) + SWAP_CLUSTER_MAX + |
| balance_gap, 0, 0))) { |
| if (lmk_fast_run) |
| tune_lmk_zone_param(zonelist, classzone_idx, other_free, |
| other_file, use_cma_pages); |
| else |
| tune_lmk_zone_param(zonelist, classzone_idx, other_free, |
| NULL, use_cma_pages); |
| |
| if (zone_watermark_ok(preferred_zone, 0, 0, _ZONE, 0)) { |
| if (!use_cma_pages) { |
| *other_free -= min( |
| preferred_zone->lowmem_reserve[_ZONE] |
| + zone_page_state( |
| preferred_zone, NR_FREE_CMA_PAGES), |
| zone_page_state( |
| preferred_zone, NR_FREE_PAGES)); |
| } else { |
| *other_free -= |
| preferred_zone->lowmem_reserve[_ZONE]; |
| } |
| } else { |
| *other_free -= zone_page_state(preferred_zone, |
| NR_FREE_PAGES); |
| } |
| |
| lowmem_print(4, "lowmem_shrink of kswapd tunning for highmem " |
| "ofree %d, %d\n", *other_free, *other_file); |
| } else { |
| tune_lmk_zone_param(zonelist, classzone_idx, other_free, |
| other_file, use_cma_pages); |
| |
| if (!use_cma_pages) { |
| *other_free -= |
| zone_page_state(preferred_zone, NR_FREE_CMA_PAGES); |
| } |
| |
| lowmem_print(4, "lowmem_shrink tunning for others ofree %d, " |
| "%d\n", *other_free, *other_file); |
| } |
| } |
| |
| static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc) |
| { |
| struct task_struct *tsk; |
| struct task_struct *selected = NULL; |
| int rem = 0; |
| int tasksize; |
| int i; |
| int min_score_adj = OOM_SCORE_ADJ_MAX + 1; |
| int selected_tasksize = 0; |
| int selected_oom_score_adj; |
| int array_size = ARRAY_SIZE(lowmem_adj); |
| int other_free; |
| int other_file; |
| unsigned long nr_to_scan = sc->nr_to_scan; |
| |
| if (nr_to_scan > 0) { |
| if (mutex_lock_interruptible(&scan_mutex) < 0) |
| return 0; |
| } |
| |
| other_free = global_page_state(NR_FREE_PAGES); |
| other_file = global_page_state(NR_FILE_PAGES) - |
| global_page_state(NR_SHMEM); |
| |
| tune_lmk_param(&other_free, &other_file, sc); |
| |
| if (lowmem_adj_size < array_size) |
| array_size = lowmem_adj_size; |
| if (lowmem_minfree_size < array_size) |
| array_size = lowmem_minfree_size; |
| for (i = 0; i < array_size; i++) { |
| if (other_free < lowmem_minfree[i] && |
| other_file < lowmem_minfree[i]) { |
| min_score_adj = lowmem_adj[i]; |
| break; |
| } |
| } |
| if (nr_to_scan > 0) |
| lowmem_print(3, "lowmem_shrink %lu, %x, ofree %d %d, ma %d\n", |
| nr_to_scan, sc->gfp_mask, other_free, |
| other_file, min_score_adj); |
| rem = global_page_state(NR_ACTIVE_ANON) + |
| global_page_state(NR_ACTIVE_FILE) + |
| global_page_state(NR_INACTIVE_ANON) + |
| global_page_state(NR_INACTIVE_FILE); |
| if (nr_to_scan <= 0 || min_score_adj == OOM_SCORE_ADJ_MAX + 1) { |
| lowmem_print(5, "lowmem_shrink %lu, %x, return %d\n", |
| nr_to_scan, sc->gfp_mask, rem); |
| |
| if (nr_to_scan > 0) |
| mutex_unlock(&scan_mutex); |
| |
| return rem; |
| } |
| selected_oom_score_adj = min_score_adj; |
| |
| rcu_read_lock(); |
| for_each_process(tsk) { |
| struct task_struct *p; |
| int oom_score_adj; |
| |
| if (tsk->flags & PF_KTHREAD) |
| continue; |
| |
| /* if task no longer has any memory ignore it */ |
| if (test_task_flag(tsk, TIF_MM_RELEASED)) |
| continue; |
| |
| if (time_before_eq(jiffies, lowmem_deathpending_timeout)) { |
| if (test_task_flag(tsk, TIF_MEMDIE)) { |
| rcu_read_unlock(); |
| /* give the system time to free up the memory */ |
| msleep_interruptible(20); |
| mutex_unlock(&scan_mutex); |
| return 0; |
| } |
| } |
| |
| p = find_lock_task_mm(tsk); |
| if (!p) |
| continue; |
| |
| oom_score_adj = p->signal->oom_score_adj; |
| if (oom_score_adj < min_score_adj) { |
| task_unlock(p); |
| continue; |
| } |
| tasksize = get_mm_rss(p->mm); |
| task_unlock(p); |
| if (tasksize <= 0) |
| continue; |
| if (selected) { |
| if (oom_score_adj < selected_oom_score_adj) |
| continue; |
| if (oom_score_adj == selected_oom_score_adj && |
| tasksize <= selected_tasksize) |
| continue; |
| } |
| selected = p; |
| selected_tasksize = tasksize; |
| selected_oom_score_adj = oom_score_adj; |
| lowmem_print(2, "select %d (%s), adj %d, size %d, to kill\n", |
| p->pid, p->comm, oom_score_adj, tasksize); |
| } |
| if (selected) { |
| lowmem_print(1, "send sigkill to %d (%s), adj %d, size %d\n", |
| selected->pid, selected->comm, |
| selected_oom_score_adj, selected_tasksize); |
| lowmem_deathpending_timeout = jiffies + HZ; |
| send_sig(SIGKILL, selected, 0); |
| set_tsk_thread_flag(selected, TIF_MEMDIE); |
| rem -= selected_tasksize; |
| rcu_read_unlock(); |
| /* give the system time to free up the memory */ |
| msleep_interruptible(20); |
| } else |
| rcu_read_unlock(); |
| |
| lowmem_print(4, "lowmem_shrink %lu, %x, return %d\n", |
| nr_to_scan, sc->gfp_mask, rem); |
| mutex_unlock(&scan_mutex); |
| return rem; |
| } |
| |
| static struct shrinker lowmem_shrinker = { |
| .shrink = lowmem_shrink, |
| .seeks = DEFAULT_SEEKS * 16 |
| }; |
| |
| static int __init lowmem_init(void) |
| { |
| register_shrinker(&lowmem_shrinker); |
| return 0; |
| } |
| |
| static void __exit lowmem_exit(void) |
| { |
| unregister_shrinker(&lowmem_shrinker); |
| } |
| |
| #ifdef CONFIG_ANDROID_LOW_MEMORY_KILLER_AUTODETECT_OOM_ADJ_VALUES |
| static int lowmem_oom_adj_to_oom_score_adj(int oom_adj) |
| { |
| if (oom_adj == OOM_ADJUST_MAX) |
| return OOM_SCORE_ADJ_MAX; |
| else |
| return (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; |
| } |
| |
| static void lowmem_autodetect_oom_adj_values(void) |
| { |
| int i; |
| int oom_adj; |
| int oom_score_adj; |
| int array_size = ARRAY_SIZE(lowmem_adj); |
| |
| if (lowmem_adj_size < array_size) |
| array_size = lowmem_adj_size; |
| |
| if (array_size <= 0) |
| return; |
| |
| oom_adj = lowmem_adj[array_size - 1]; |
| if (oom_adj > OOM_ADJUST_MAX) |
| return; |
| |
| oom_score_adj = lowmem_oom_adj_to_oom_score_adj(oom_adj); |
| if (oom_score_adj <= OOM_ADJUST_MAX) |
| return; |
| |
| lowmem_print(1, "lowmem_shrink: convert oom_adj to oom_score_adj:\n"); |
| for (i = 0; i < array_size; i++) { |
| oom_adj = lowmem_adj[i]; |
| oom_score_adj = lowmem_oom_adj_to_oom_score_adj(oom_adj); |
| lowmem_adj[i] = oom_score_adj; |
| lowmem_print(1, "oom_adj %d => oom_score_adj %d\n", |
| oom_adj, oom_score_adj); |
| } |
| } |
| |
| static int lowmem_adj_array_set(const char *val, const struct kernel_param *kp) |
| { |
| int ret; |
| |
| ret = param_array_ops.set(val, kp); |
| |
| /* HACK: Autodetect oom_adj values in lowmem_adj array */ |
| lowmem_autodetect_oom_adj_values(); |
| |
| return ret; |
| } |
| |
| static int lowmem_adj_array_get(char *buffer, const struct kernel_param *kp) |
| { |
| return param_array_ops.get(buffer, kp); |
| } |
| |
| static void lowmem_adj_array_free(void *arg) |
| { |
| param_array_ops.free(arg); |
| } |
| |
| static struct kernel_param_ops lowmem_adj_array_ops = { |
| .set = lowmem_adj_array_set, |
| .get = lowmem_adj_array_get, |
| .free = lowmem_adj_array_free, |
| }; |
| |
| static const struct kparam_array __param_arr_adj = { |
| .max = ARRAY_SIZE(lowmem_adj), |
| .num = &lowmem_adj_size, |
| .ops = ¶m_ops_int, |
| .elemsize = sizeof(lowmem_adj[0]), |
| .elem = lowmem_adj, |
| }; |
| #endif |
| |
| module_param_named(cost, lowmem_shrinker.seeks, int, S_IRUGO | S_IWUSR); |
| #ifdef CONFIG_ANDROID_LOW_MEMORY_KILLER_AUTODETECT_OOM_ADJ_VALUES |
| __module_param_call(MODULE_PARAM_PREFIX, adj, |
| &lowmem_adj_array_ops, |
| .arr = &__param_arr_adj, |
| S_IRUGO | S_IWUSR, -1); |
| __MODULE_PARM_TYPE(adj, "array of int"); |
| #else |
| module_param_array_named(adj, lowmem_adj, int, &lowmem_adj_size, |
| S_IRUGO | S_IWUSR); |
| #endif |
| module_param_array_named(minfree, lowmem_minfree, uint, &lowmem_minfree_size, |
| S_IRUGO | S_IWUSR); |
| module_param_named(debug_level, lowmem_debug_level, uint, S_IRUGO | S_IWUSR); |
| module_param_named(lmk_fast_run, lmk_fast_run, int, S_IRUGO | S_IWUSR); |
| |
| module_init(lowmem_init); |
| module_exit(lowmem_exit); |
| |
| MODULE_LICENSE("GPL"); |
| |