1 /* 2 * Copyright (c) 2006-2019 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 * 28 */ 29 30 #ifndef _KERN_MEMORYSTATUS_INTERNAL_H_ 31 #define _KERN_MEMORYSTATUS_INTERNAL_H_ 32 33 /* 34 * Contains memorystatus subsystem definitions that are not 35 * exported outside of the memorystatus subsystem. 36 * 37 * For example, all of the mechanisms used by kern_memorystatus_policy.c 38 * should be defined in this header. 39 */ 40 41 #if BSD_KERNEL_PRIVATE 42 43 #include <mach/boolean.h> 44 #include <stdbool.h> 45 #include <os/base.h> 46 #include <kern/sched_prim.h> 47 48 #if CONFIG_FREEZE 49 #include <sys/kern_memorystatus_freeze.h> 50 #endif /* CONFIG_FREEZE */ 51 52 /* 53 * memorystatus subsystem globals 54 */ 55 #if CONFIG_JETSAM 56 extern unsigned int memorystatus_available_pages; 57 extern unsigned int memorystatus_available_pages_pressure; 58 extern unsigned int memorystatus_available_pages_critical; 59 extern uint32_t jetsam_kill_on_low_swap; 60 #else /* CONFIG_JETSAM */ 61 extern uint64_t memorystatus_available_pages; 62 extern uint64_t memorystatus_available_pages_pressure; 63 extern uint64_t memorystatus_available_pages_critical; 64 #endif /* CONFIG_JETSAM */ 65 extern int block_corpses; /* counter to block new corpses if jetsam purges them */ 66 extern int system_procs_aging_band; 67 extern int applications_aging_band; 68 /* 69 * TODO(jason): This should really be calculated dynamically by the zalloc 70 * subsystem before we do a zone map exhaustion kill. But the zone_gc 71 * logic is non-trivial, so for now it just sets this global. 72 */ 73 extern _Atomic bool memorystatus_zone_map_is_exhausted; 74 /* 75 * TODO(jason): We should get rid of this global 76 * and have the memorystatus thread check for compressor space shortages 77 * itself. However, there are 3 async call sites remaining that require more work to get us there: 78 * 2 of them are in vm_swap_defragment. When it's about to swap in a segment, it checks if that 79 * will cause a compressor space shortage & pre-emptively triggers jetsam. vm_compressor_backing_store 80 * needs to keep track of in-flight swapins due to defrag so we can perform those checks 81 * in the memorystatus thread. 82 * The other is in no_paging_space_action. This is only on macOS right now, but will 83 * be needed on iPad when we run out of swap space. This should be a new kill 84 * reason and we need to add a new health check for it. 85 * We need to maintain the macOS behavior though that we kill no more than 1 process 86 * every 5 seconds. 87 */ 88 extern _Atomic bool memorystatus_compressor_space_shortage; 89 /* 90 * TODO(jason): We should also get rid of this global 91 * and check for phantom cache pressure from the memorystatus 92 * thread. But first we need to fix the syncronization in 93 * vm_phantom_cache_check_pressure 94 */ 95 extern _Atomic bool memorystatus_phantom_cache_pressure; 96 97 /* 98 * The actions that the memorystatus thread can perform 99 * when we're low on memory. 100 * See memorystatus_pick_action to see when each action is deployed. 101 */ 102 OS_CLOSED_ENUM(memorystatus_action, uint32_t, 103 MEMORYSTATUS_KILL_HIWATER, // Kill 1 highwatermark process 104 MEMORYSTATUS_KILL_AGGRESSIVE, // Do aggressive jetsam 105 MEMORYSTATUS_KILL_TOP_PROCESS, // Kill based on jetsam priority 106 MEMORYSTATUS_WAKE_SWAPPER, // Wake up the swap thread 107 MEMORYSTATUS_PROCESS_SWAPIN_QUEUE, // Compact the swapin queue and move segments to the swapout queue 108 MEMORYSTATUS_KILL_SUSPENDED_SWAPPABLE, // Kill a suspended swap-eligible processes based on jetsam priority 109 MEMORYSTATUS_KILL_SWAPPABLE, // Kill a swap-eligible process (even if it's running) based on jetsam priority 110 MEMORYSTATUS_KILL_NONE, // Do nothing 111 ); 112 113 /* 114 * Structure to hold state for a jetsam thread. 115 * Typically there should be a single jetsam thread 116 * unless parallel jetsam is enabled. 117 */ 118 typedef struct jetsam_thread_state { 119 uint8_t inited; /* boolean - if the thread is initialized */ 120 uint8_t limit_to_low_bands; /* boolean */ 121 int index; /* jetsam thread index */ 122 thread_t thread; /* jetsam thread pointer */ 123 int jld_idle_kills; /* idle jetsam kill counter for this session */ 124 uint32_t errors; /* Error accumulator */ 125 bool sort_flag; /* Sort the fg band (idle on macOS) before killing? */ 126 bool corpse_list_purged; /* Has the corpse list been purged? */ 127 bool post_snapshot; /* Do we need to post a jetsam snapshot after this session? */ 128 uint64_t memory_reclaimed; /* Amount of memory that was just reclaimed */ 129 uint32_t hwm_kills; /* hwm kill counter for this session */ 130 sched_cond_atomic_t jt_wakeup_cond; /* condition var used to synchronize wake/sleep operations for this jetsam thread */ 131 } jetsam_thread_state_t; 132 133 /* 134 * The memorystatus thread monitors these conditions 135 * and will continue to act until the system is considered 136 * healthy. 137 */ 138 typedef struct memorystatus_system_health { 139 #if CONFIG_JETSAM 140 bool msh_available_pages_below_pressure; 141 bool msh_available_pages_below_critical; 142 bool msh_compressor_needs_to_swap; 143 bool msh_compressor_is_low_on_space; 144 bool msh_compressor_is_thrashing; 145 bool msh_compressed_pages_nearing_limit; 146 bool msh_filecache_is_thrashing; 147 bool msh_phantom_cache_pressure; 148 bool msh_swappable_compressor_segments_over_limit; 149 bool msh_swapin_queue_over_limit; 150 bool msh_swap_low_on_space; 151 bool msh_swap_out_of_space; 152 #endif /* CONFIG_JETSAM */ 153 bool msh_zone_map_is_exhausted; 154 } memorystatus_system_health_t; 155 156 void memorystatus_log_system_health(const memorystatus_system_health_t *health); 157 bool memorystatus_is_system_healthy(const memorystatus_system_health_t *status); 158 /* Picks a kill cause given an unhealthy system status */ 159 uint32_t memorystatus_pick_kill_cause(const memorystatus_system_health_t *status); 160 161 /* 162 * Agressive jetsam tunables 163 */ 164 #define kJetsamAgingPolicyNone (0) 165 #define kJetsamAgingPolicyLegacy (1) 166 #define kJetsamAgingPolicySysProcsReclaimedFirst (2) 167 #define kJetsamAgingPolicyAppsReclaimedFirst (3) 168 #define kJetsamAgingPolicyMax kJetsamAgingPolicyAppsReclaimedFirst 169 extern boolean_t memorystatus_jld_enabled; /* Enable jetsam loop detection */ 170 extern uint32_t memorystatus_jld_eval_period_msecs; /* Init pass sets this based on device memory size */ 171 extern int memorystatus_jld_eval_aggressive_count; /* Raise the priority max after 'n' aggressive loops */ 172 extern int memorystatus_jld_eval_aggressive_priority_band_max; /* Kill aggressively up through this band */ 173 extern int memorystatus_jld_max_kill_loops; /* How many times should we try and kill up to the target band */ 174 extern unsigned int memorystatus_sysproc_aging_aggr_pages; /* Aggressive jetsam pages threshold for sysproc aging policy */ 175 extern int jld_eval_aggressive_count; 176 extern int32_t jld_priority_band_max; 177 extern uint64_t jld_timestamp_msecs; 178 extern int jld_idle_kill_candidates; 179 180 181 /* 182 * VM globals read by the memorystatus subsystem 183 */ 184 extern unsigned int vm_page_free_count; 185 extern unsigned int vm_page_active_count; 186 extern unsigned int vm_page_inactive_count; 187 extern unsigned int vm_page_throttled_count; 188 extern unsigned int vm_page_purgeable_count; 189 extern unsigned int vm_page_wire_count; 190 extern unsigned int vm_page_speculative_count; 191 extern uint32_t c_late_swapout_count, c_late_swappedin_count; 192 extern uint32_t c_seg_allocsize; 193 extern bool vm_swapout_thread_running; 194 extern _Atomic bool vm_swapout_wake_pending; 195 #define VM_PAGE_DONATE_DISABLED 0 196 #define VM_PAGE_DONATE_ENABLED 1 197 extern uint32_t vm_page_donate_mode; 198 void vm_swapout_thread(void); 199 void vm_compressor_process_special_swapped_in_segments(void); 200 201 #if CONFIG_JETSAM 202 #define MEMORYSTATUS_LOG_AVAILABLE_PAGES memorystatus_available_pages 203 #else /* CONFIG_JETSAM */ 204 #define MEMORYSTATUS_LOG_AVAILABLE_PAGES (vm_page_active_count + vm_page_inactive_count + vm_page_free_count + vm_page_speculative_count) 205 #endif /* CONFIG_JETSAM */ 206 207 bool memorystatus_avail_pages_below_pressure(void); 208 bool memorystatus_avail_pages_below_critical(void); 209 #if CONFIG_JETSAM 210 bool memorystatus_swap_over_trigger(uint64_t adjustment_factor); 211 bool memorystatus_swapin_over_trigger(void); 212 #endif /* CONFIG_JETSAM */ 213 214 /* Does cause indicate vm or fc thrashing? */ 215 bool is_reason_thrashing(unsigned cause); 216 /* Is the zone map almost full? */ 217 bool is_reason_zone_map_exhaustion(unsigned cause); 218 219 memorystatus_action_t memorystatus_pick_action(struct jetsam_thread_state *jetsam_thread, 220 uint32_t *kill_cause, bool highwater_remaining, 221 bool suspended_swappable_apps_remaining, 222 bool swappable_apps_remaining, int *jld_idle_kills); 223 224 #pragma mark Freezer 225 #if CONFIG_FREEZE 226 /* 227 * Freezer data types 228 */ 229 230 /* An ordered list of freeze or demotion candidates */ 231 struct memorystatus_freezer_candidate_list { 232 memorystatus_properties_freeze_entry_v1 *mfcl_list; 233 size_t mfcl_length; 234 }; 235 236 struct memorystatus_freeze_list_iterator { 237 bool refreeze_only; 238 proc_t last_p; 239 size_t global_freeze_list_index; 240 }; 241 242 /* 243 * Freezer globals 244 */ 245 extern struct memorystatus_freezer_stats_t memorystatus_freezer_stats; 246 extern int memorystatus_freezer_use_ordered_list; 247 extern struct memorystatus_freezer_candidate_list memorystatus_global_freeze_list; 248 extern struct memorystatus_freezer_candidate_list memorystatus_global_demote_list; 249 extern uint64_t memorystatus_freezer_thread_next_run_ts; 250 bool memorystatus_is_process_eligible_for_freeze(proc_t p); 251 bool memorystatus_freeze_proc_is_refreeze_eligible(proc_t p); 252 253 proc_t memorystatus_freezer_candidate_list_get_proc( 254 struct memorystatus_freezer_candidate_list *list, 255 size_t index, 256 uint64_t *pid_mismatch_counter); 257 /* 258 * Returns the leader of the p's jetsam coalition 259 * and the role of p in that coalition. 260 */ 261 proc_t memorystatus_get_coalition_leader_and_role(proc_t p, int *role_in_coalition); 262 bool memorystatus_freeze_process_is_recommended(const proc_t p); 263 264 /* 265 * Ordered iterator over all freeze candidates. 266 * The iterator should initially be zeroed out by the caller and 267 * can be zeroed out whenever the caller wishes to start from the beginning 268 * of the list again. 269 * Returns PROC_NULL when all candidates have been iterated over. 270 */ 271 proc_t memorystatus_freeze_pick_process(struct memorystatus_freeze_list_iterator *iterator); 272 273 /* 274 * Returns the number of processes that the freezer thread should try to freeze 275 * on this wakeup. 276 */ 277 size_t memorystatus_pick_freeze_count_for_wakeup(void); 278 279 /* 280 * Configure the freezer for app-based swap mode. 281 * Should be called at boot. 282 */ 283 void memorystatus_freeze_configure_for_swap(void); 284 /* 285 * Undo memorystatus_freeze_configure_for_swap 286 */ 287 void memorystatus_freeze_disable_swap(void); 288 #endif /* CONFIG_FREEZE */ 289 290 #endif /* BSD_KERNEL_PRIVATE */ 291 292 #endif /* _KERN_MEMORYSTATUS_INTERNAL_H_ */ 293