Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/mm/oom_kill.c |
| 3 | * |
| 4 | * Copyright (C) 1998,2000 Rik van Riel |
| 5 | * Thanks go out to Claus Fischer for some serious inspiration and |
| 6 | * for goading me into coding this file... |
| 7 | * |
| 8 | * The routines in this file are used to kill a process when |
Paul Jackson | a49335c | 2005-09-06 15:18:09 -0700 | [diff] [blame] | 9 | * we're seriously out of memory. This gets called from __alloc_pages() |
| 10 | * in mm/page_alloc.c when we really run out of memory. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | * |
| 12 | * Since we won't call these routines often (on a well-configured |
| 13 | * machine) this file will double as a 'coding guide' and a signpost |
| 14 | * for newbie kernel hackers. It features several pointers to major |
| 15 | * kernel subsystems and hints as to where to find out what things do. |
| 16 | */ |
| 17 | |
| 18 | #include <linux/mm.h> |
| 19 | #include <linux/sched.h> |
| 20 | #include <linux/swap.h> |
| 21 | #include <linux/timex.h> |
| 22 | #include <linux/jiffies.h> |
Paul Jackson | ef08e3b | 2005-09-06 15:18:13 -0700 | [diff] [blame] | 23 | #include <linux/cpuset.h> |
Martin Schwidefsky | 8bc719d | 2006-09-25 23:31:20 -0700 | [diff] [blame] | 24 | #include <linux/module.h> |
| 25 | #include <linux/notifier.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | |
KAMEZAWA Hiroyuki | fadd8fb | 2006-06-23 02:03:13 -0700 | [diff] [blame] | 27 | int sysctl_panic_on_oom; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | /* #define DEBUG */ |
| 29 | |
| 30 | /** |
Dave Peterson | 6937a25 | 2006-06-23 02:03:13 -0700 | [diff] [blame] | 31 | * badness - calculate a numeric value for how bad this task has been |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | * @p: task struct of which task we should calculate |
Paul Jackson | a49335c | 2005-09-06 15:18:09 -0700 | [diff] [blame] | 33 | * @uptime: current uptime in seconds |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | * |
| 35 | * The formula used is relatively simple and documented inline in the |
| 36 | * function. The main rationale is that we want to select a good task |
| 37 | * to kill when we run out of memory. |
| 38 | * |
| 39 | * Good in this context means that: |
| 40 | * 1) we lose the minimum amount of work done |
| 41 | * 2) we recover a large amount of memory |
| 42 | * 3) we don't kill anything innocent of eating tons of memory |
| 43 | * 4) we want to kill the minimum amount of processes (one) |
| 44 | * 5) we try to kill the process the user expects us to kill, this |
| 45 | * algorithm has been meticulously tuned to meet the principle |
| 46 | * of least surprise ... (be careful when you change it) |
| 47 | */ |
| 48 | |
| 49 | unsigned long badness(struct task_struct *p, unsigned long uptime) |
| 50 | { |
| 51 | unsigned long points, cpu_time, run_time, s; |
Andrew Morton | 97c2c9b | 2006-04-18 22:20:38 -0700 | [diff] [blame] | 52 | struct mm_struct *mm; |
| 53 | struct task_struct *child; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | |
Andrew Morton | 97c2c9b | 2006-04-18 22:20:38 -0700 | [diff] [blame] | 55 | task_lock(p); |
| 56 | mm = p->mm; |
| 57 | if (!mm) { |
| 58 | task_unlock(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | return 0; |
Andrew Morton | 97c2c9b | 2006-04-18 22:20:38 -0700 | [diff] [blame] | 60 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | |
| 62 | /* |
| 63 | * The memory size of the process is the basis for the badness. |
| 64 | */ |
Andrew Morton | 97c2c9b | 2006-04-18 22:20:38 -0700 | [diff] [blame] | 65 | points = mm->total_vm; |
| 66 | |
| 67 | /* |
| 68 | * After this unlock we can no longer dereference local variable `mm' |
| 69 | */ |
| 70 | task_unlock(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | |
| 72 | /* |
| 73 | * Processes which fork a lot of child processes are likely |
Kurt Garloff | 9827b78 | 2006-02-20 18:27:51 -0800 | [diff] [blame] | 74 | * a good choice. We add half the vmsize of the children if they |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | * have an own mm. This prevents forking servers to flood the |
Kurt Garloff | 9827b78 | 2006-02-20 18:27:51 -0800 | [diff] [blame] | 76 | * machine with an endless amount of children. In case a single |
| 77 | * child is eating the vast majority of memory, adding only half |
| 78 | * to the parents will make the child our kill candidate of choice. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | */ |
Andrew Morton | 97c2c9b | 2006-04-18 22:20:38 -0700 | [diff] [blame] | 80 | list_for_each_entry(child, &p->children, sibling) { |
| 81 | task_lock(child); |
| 82 | if (child->mm != mm && child->mm) |
| 83 | points += child->mm->total_vm/2 + 1; |
| 84 | task_unlock(child); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | } |
| 86 | |
| 87 | /* |
| 88 | * CPU time is in tens of seconds and run time is in thousands |
| 89 | * of seconds. There is no particular reason for this other than |
| 90 | * that it turned out to work very well in practice. |
| 91 | */ |
| 92 | cpu_time = (cputime_to_jiffies(p->utime) + cputime_to_jiffies(p->stime)) |
| 93 | >> (SHIFT_HZ + 3); |
| 94 | |
| 95 | if (uptime >= p->start_time.tv_sec) |
| 96 | run_time = (uptime - p->start_time.tv_sec) >> 10; |
| 97 | else |
| 98 | run_time = 0; |
| 99 | |
| 100 | s = int_sqrt(cpu_time); |
| 101 | if (s) |
| 102 | points /= s; |
| 103 | s = int_sqrt(int_sqrt(run_time)); |
| 104 | if (s) |
| 105 | points /= s; |
| 106 | |
| 107 | /* |
| 108 | * Niced processes are most likely less important, so double |
| 109 | * their badness points. |
| 110 | */ |
| 111 | if (task_nice(p) > 0) |
| 112 | points *= 2; |
| 113 | |
| 114 | /* |
| 115 | * Superuser processes are usually more important, so we make it |
| 116 | * less likely that we kill those. |
| 117 | */ |
| 118 | if (cap_t(p->cap_effective) & CAP_TO_MASK(CAP_SYS_ADMIN) || |
| 119 | p->uid == 0 || p->euid == 0) |
| 120 | points /= 4; |
| 121 | |
| 122 | /* |
| 123 | * We don't want to kill a process with direct hardware access. |
| 124 | * Not only could that mess up the hardware, but usually users |
| 125 | * tend to only have this flag set on applications they think |
| 126 | * of as important. |
| 127 | */ |
| 128 | if (cap_t(p->cap_effective) & CAP_TO_MASK(CAP_SYS_RAWIO)) |
| 129 | points /= 4; |
| 130 | |
| 131 | /* |
Nick Piggin | 7887a3d | 2006-09-25 23:31:29 -0700 | [diff] [blame] | 132 | * If p's nodes don't overlap ours, it may still help to kill p |
| 133 | * because p may have allocated or otherwise mapped memory on |
| 134 | * this node before. However it will be less likely. |
| 135 | */ |
| 136 | if (!cpuset_excl_nodes_overlap(p)) |
| 137 | points /= 8; |
| 138 | |
| 139 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | * Adjust the score by oomkilladj. |
| 141 | */ |
| 142 | if (p->oomkilladj) { |
| 143 | if (p->oomkilladj > 0) |
| 144 | points <<= p->oomkilladj; |
| 145 | else |
| 146 | points >>= -(p->oomkilladj); |
| 147 | } |
| 148 | |
| 149 | #ifdef DEBUG |
| 150 | printk(KERN_DEBUG "OOMkill: task %d (%s) got %d points\n", |
| 151 | p->pid, p->comm, points); |
| 152 | #endif |
| 153 | return points; |
| 154 | } |
| 155 | |
| 156 | /* |
Christoph Lameter | 9b0f8b0 | 2006-02-20 18:27:52 -0800 | [diff] [blame] | 157 | * Types of limitations to the nodes from which allocations may occur |
| 158 | */ |
| 159 | #define CONSTRAINT_NONE 1 |
| 160 | #define CONSTRAINT_MEMORY_POLICY 2 |
| 161 | #define CONSTRAINT_CPUSET 3 |
| 162 | |
| 163 | /* |
| 164 | * Determine the type of allocation constraint. |
| 165 | */ |
| 166 | static inline int constrained_alloc(struct zonelist *zonelist, gfp_t gfp_mask) |
| 167 | { |
| 168 | #ifdef CONFIG_NUMA |
| 169 | struct zone **z; |
| 170 | nodemask_t nodes = node_online_map; |
| 171 | |
| 172 | for (z = zonelist->zones; *z; z++) |
| 173 | if (cpuset_zone_allowed(*z, gfp_mask)) |
| 174 | node_clear((*z)->zone_pgdat->node_id, |
| 175 | nodes); |
| 176 | else |
| 177 | return CONSTRAINT_CPUSET; |
| 178 | |
| 179 | if (!nodes_empty(nodes)) |
| 180 | return CONSTRAINT_MEMORY_POLICY; |
| 181 | #endif |
| 182 | |
| 183 | return CONSTRAINT_NONE; |
| 184 | } |
| 185 | |
| 186 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | * Simple selection loop. We chose the process with the highest |
| 188 | * number of 'points'. We expect the caller will lock the tasklist. |
| 189 | * |
| 190 | * (not docbooked, we don't want this one cluttering up the manual) |
| 191 | */ |
Kurt Garloff | 9827b78 | 2006-02-20 18:27:51 -0800 | [diff] [blame] | 192 | static struct task_struct *select_bad_process(unsigned long *ppoints) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | struct task_struct *g, *p; |
| 195 | struct task_struct *chosen = NULL; |
| 196 | struct timespec uptime; |
Kurt Garloff | 9827b78 | 2006-02-20 18:27:51 -0800 | [diff] [blame] | 197 | *ppoints = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | |
| 199 | do_posix_clock_monotonic_gettime(&uptime); |
Paul Jackson | a49335c | 2005-09-06 15:18:09 -0700 | [diff] [blame] | 200 | do_each_thread(g, p) { |
| 201 | unsigned long points; |
| 202 | int releasing; |
| 203 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | /* skip the init task with pid == 1 */ |
Paul Jackson | a49335c | 2005-09-06 15:18:09 -0700 | [diff] [blame] | 205 | if (p->pid == 1) |
| 206 | continue; |
| 207 | if (p->oomkilladj == OOM_DISABLE) |
| 208 | continue; |
Paul Jackson | ef08e3b | 2005-09-06 15:18:13 -0700 | [diff] [blame] | 209 | |
Paul Jackson | a49335c | 2005-09-06 15:18:09 -0700 | [diff] [blame] | 210 | /* |
Dave Peterson | 6937a25 | 2006-06-23 02:03:13 -0700 | [diff] [blame] | 211 | * This is in the process of releasing memory so wait for it |
Paul Jackson | a49335c | 2005-09-06 15:18:09 -0700 | [diff] [blame] | 212 | * to finish before killing some other task by mistake. |
Nick Piggin | 50ec3bb | 2006-09-25 23:31:29 -0700 | [diff] [blame^] | 213 | * |
| 214 | * However, if p is the current task, we allow the 'kill' to |
| 215 | * go ahead if it is exiting: this will simply set TIF_MEMDIE, |
| 216 | * which will allow it to gain access to memory reserves in |
| 217 | * the process of exiting and releasing its resources. |
| 218 | * Otherwise we could get an OOM deadlock. |
Paul Jackson | a49335c | 2005-09-06 15:18:09 -0700 | [diff] [blame] | 219 | */ |
| 220 | releasing = test_tsk_thread_flag(p, TIF_MEMDIE) || |
| 221 | p->flags & PF_EXITING; |
Nick Piggin | 50ec3bb | 2006-09-25 23:31:29 -0700 | [diff] [blame^] | 222 | if (releasing) { |
| 223 | /* PF_DEAD tasks have already released their mm */ |
| 224 | if (p->flags & PF_DEAD) |
| 225 | continue; |
| 226 | if (p->flags & PF_EXITING && p == current) { |
| 227 | chosen = p; |
| 228 | *ppoints = ULONG_MAX; |
| 229 | break; |
| 230 | } |
Paul Jackson | a49335c | 2005-09-06 15:18:09 -0700 | [diff] [blame] | 231 | return ERR_PTR(-1UL); |
Nick Piggin | 50ec3bb | 2006-09-25 23:31:29 -0700 | [diff] [blame^] | 232 | } |
Paul Jackson | a49335c | 2005-09-06 15:18:09 -0700 | [diff] [blame] | 233 | if (p->flags & PF_SWAPOFF) |
| 234 | return p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | |
Paul Jackson | a49335c | 2005-09-06 15:18:09 -0700 | [diff] [blame] | 236 | points = badness(p, uptime.tv_sec); |
Kurt Garloff | 9827b78 | 2006-02-20 18:27:51 -0800 | [diff] [blame] | 237 | if (points > *ppoints || !chosen) { |
Paul Jackson | a49335c | 2005-09-06 15:18:09 -0700 | [diff] [blame] | 238 | chosen = p; |
Kurt Garloff | 9827b78 | 2006-02-20 18:27:51 -0800 | [diff] [blame] | 239 | *ppoints = points; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | } |
Paul Jackson | a49335c | 2005-09-06 15:18:09 -0700 | [diff] [blame] | 241 | } while_each_thread(g, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | return chosen; |
| 243 | } |
| 244 | |
| 245 | /** |
| 246 | * We must be careful though to never send SIGKILL a process with |
| 247 | * CAP_SYS_RAW_IO set, send SIGTERM instead (but it's unlikely that |
| 248 | * we select a process with CAP_SYS_RAW_IO set). |
| 249 | */ |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 250 | static void __oom_kill_task(struct task_struct *p, const char *message) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | { |
| 252 | if (p->pid == 1) { |
| 253 | WARN_ON(1); |
| 254 | printk(KERN_WARNING "tried to kill init!\n"); |
| 255 | return; |
| 256 | } |
| 257 | |
| 258 | task_lock(p); |
| 259 | if (!p->mm || p->mm == &init_mm) { |
| 260 | WARN_ON(1); |
| 261 | printk(KERN_WARNING "tried to kill an mm-less task!\n"); |
| 262 | task_unlock(p); |
| 263 | return; |
| 264 | } |
| 265 | task_unlock(p); |
Nick Piggin | 50ec3bb | 2006-09-25 23:31:29 -0700 | [diff] [blame^] | 266 | |
| 267 | if (message) { |
| 268 | printk(KERN_ERR "%s: Killed process %d (%s).\n", |
Christoph Lameter | 9b0f8b0 | 2006-02-20 18:27:52 -0800 | [diff] [blame] | 269 | message, p->pid, p->comm); |
Nick Piggin | 50ec3bb | 2006-09-25 23:31:29 -0700 | [diff] [blame^] | 270 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | |
| 272 | /* |
| 273 | * We give our sacrificial lamb high priority and access to |
| 274 | * all the memory it needs. That way it should be able to |
| 275 | * exit() and clear out its resources quickly... |
| 276 | */ |
| 277 | p->time_slice = HZ; |
| 278 | set_tsk_thread_flag(p, TIF_MEMDIE); |
| 279 | |
| 280 | force_sig(SIGKILL, p); |
| 281 | } |
| 282 | |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 283 | static int oom_kill_task(struct task_struct *p, const char *message) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | { |
Dave Peterson | 0131592 | 2006-04-18 22:20:44 -0700 | [diff] [blame] | 285 | struct mm_struct *mm; |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 286 | struct task_struct *g, *q; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | |
Dave Peterson | 0131592 | 2006-04-18 22:20:44 -0700 | [diff] [blame] | 288 | mm = p->mm; |
| 289 | |
| 290 | /* WARNING: mm may not be dereferenced since we did not obtain its |
| 291 | * value from get_task_mm(p). This is OK since all we need to do is |
| 292 | * compare mm to q->mm below. |
| 293 | * |
| 294 | * Furthermore, even if mm contains a non-NULL value, p->mm may |
| 295 | * change to NULL at any time since we do not hold task_lock(p). |
| 296 | * However, this is of no concern to us. |
| 297 | */ |
| 298 | |
| 299 | if (mm == NULL || mm == &init_mm) |
| 300 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | |
Christoph Lameter | 9b0f8b0 | 2006-02-20 18:27:52 -0800 | [diff] [blame] | 302 | __oom_kill_task(p, message); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | /* |
| 304 | * kill all processes that share the ->mm (i.e. all threads), |
| 305 | * but are in a different thread group |
| 306 | */ |
| 307 | do_each_thread(g, q) |
| 308 | if (q->mm == mm && q->tgid != p->tgid) |
Christoph Lameter | 9b0f8b0 | 2006-02-20 18:27:52 -0800 | [diff] [blame] | 309 | __oom_kill_task(q, message); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | while_each_thread(g, q); |
| 311 | |
Dave Peterson | 0131592 | 2006-04-18 22:20:44 -0700 | [diff] [blame] | 312 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 313 | } |
| 314 | |
Dave Peterson | 0131592 | 2006-04-18 22:20:44 -0700 | [diff] [blame] | 315 | static int oom_kill_process(struct task_struct *p, unsigned long points, |
| 316 | const char *message) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 317 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | struct task_struct *c; |
| 319 | struct list_head *tsk; |
| 320 | |
Nick Piggin | 50ec3bb | 2006-09-25 23:31:29 -0700 | [diff] [blame^] | 321 | /* |
| 322 | * If the task is already exiting, don't alarm the sysadmin or kill |
| 323 | * its children or threads, just set TIF_MEMDIE so it can die quickly |
| 324 | */ |
| 325 | if (p->flags & PF_EXITING) { |
| 326 | __oom_kill_task(p, NULL); |
| 327 | return 0; |
| 328 | } |
| 329 | |
| 330 | printk(KERN_ERR "Out of Memory: Kill process %d (%s) score %li" |
| 331 | " and children.\n", p->pid, p->comm, points); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 332 | /* Try to kill a child first */ |
| 333 | list_for_each(tsk, &p->children) { |
| 334 | c = list_entry(tsk, struct task_struct, sibling); |
| 335 | if (c->mm == p->mm) |
| 336 | continue; |
Dave Peterson | 0131592 | 2006-04-18 22:20:44 -0700 | [diff] [blame] | 337 | if (!oom_kill_task(c, message)) |
| 338 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | } |
Christoph Lameter | 9b0f8b0 | 2006-02-20 18:27:52 -0800 | [diff] [blame] | 340 | return oom_kill_task(p, message); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | } |
| 342 | |
Martin Schwidefsky | 8bc719d | 2006-09-25 23:31:20 -0700 | [diff] [blame] | 343 | static BLOCKING_NOTIFIER_HEAD(oom_notify_list); |
| 344 | |
| 345 | int register_oom_notifier(struct notifier_block *nb) |
| 346 | { |
| 347 | return blocking_notifier_chain_register(&oom_notify_list, nb); |
| 348 | } |
| 349 | EXPORT_SYMBOL_GPL(register_oom_notifier); |
| 350 | |
| 351 | int unregister_oom_notifier(struct notifier_block *nb) |
| 352 | { |
| 353 | return blocking_notifier_chain_unregister(&oom_notify_list, nb); |
| 354 | } |
| 355 | EXPORT_SYMBOL_GPL(unregister_oom_notifier); |
| 356 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | /** |
Dave Peterson | 6937a25 | 2006-06-23 02:03:13 -0700 | [diff] [blame] | 358 | * out_of_memory - kill the "best" process when we run out of memory |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | * |
| 360 | * If we run out of memory, we have the choice between either |
| 361 | * killing a random task (bad), letting the system crash (worse) |
| 362 | * OR try to be smart about which process to kill. Note that we |
| 363 | * don't have to be perfect here, we just have to be good. |
| 364 | */ |
Christoph Lameter | 9b0f8b0 | 2006-02-20 18:27:52 -0800 | [diff] [blame] | 365 | void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | { |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 367 | struct task_struct *p; |
Andrew Morton | d6713e0 | 2006-02-28 16:59:19 -0800 | [diff] [blame] | 368 | unsigned long points = 0; |
Martin Schwidefsky | 8bc719d | 2006-09-25 23:31:20 -0700 | [diff] [blame] | 369 | unsigned long freed = 0; |
| 370 | |
| 371 | blocking_notifier_call_chain(&oom_notify_list, 0, &freed); |
| 372 | if (freed > 0) |
| 373 | /* Got some memory back in the last second. */ |
| 374 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | |
Anton Blanchard | 4263926 | 2005-07-07 17:56:06 -0700 | [diff] [blame] | 376 | if (printk_ratelimit()) { |
| 377 | printk("oom-killer: gfp_mask=0x%x, order=%d\n", |
| 378 | gfp_mask, order); |
Andrew Morton | b958f7d | 2006-02-01 03:05:51 -0800 | [diff] [blame] | 379 | dump_stack(); |
Anton Blanchard | 4263926 | 2005-07-07 17:56:06 -0700 | [diff] [blame] | 380 | show_mem(); |
| 381 | } |
Janet Morgan | 578c2fd | 2005-06-21 17:14:56 -0700 | [diff] [blame] | 382 | |
Paul Jackson | 505970b | 2006-01-14 13:21:06 -0800 | [diff] [blame] | 383 | cpuset_lock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | read_lock(&tasklist_lock); |
Christoph Lameter | 9b0f8b0 | 2006-02-20 18:27:52 -0800 | [diff] [blame] | 385 | |
| 386 | /* |
| 387 | * Check if there were limitations on the allocation (only relevant for |
| 388 | * NUMA) that may require different handling. |
| 389 | */ |
| 390 | switch (constrained_alloc(zonelist, gfp_mask)) { |
| 391 | case CONSTRAINT_MEMORY_POLICY: |
Dave Peterson | 0131592 | 2006-04-18 22:20:44 -0700 | [diff] [blame] | 392 | oom_kill_process(current, points, |
Christoph Lameter | 9b0f8b0 | 2006-02-20 18:27:52 -0800 | [diff] [blame] | 393 | "No available memory (MPOL_BIND)"); |
| 394 | break; |
| 395 | |
| 396 | case CONSTRAINT_CPUSET: |
Dave Peterson | 0131592 | 2006-04-18 22:20:44 -0700 | [diff] [blame] | 397 | oom_kill_process(current, points, |
Christoph Lameter | 9b0f8b0 | 2006-02-20 18:27:52 -0800 | [diff] [blame] | 398 | "No available memory in cpuset"); |
| 399 | break; |
| 400 | |
| 401 | case CONSTRAINT_NONE: |
KAMEZAWA Hiroyuki | fadd8fb | 2006-06-23 02:03:13 -0700 | [diff] [blame] | 402 | if (sysctl_panic_on_oom) |
| 403 | panic("out of memory. panic_on_oom is selected\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 404 | retry: |
Christoph Lameter | 9b0f8b0 | 2006-02-20 18:27:52 -0800 | [diff] [blame] | 405 | /* |
| 406 | * Rambo mode: Shoot down a process and hope it solves whatever |
| 407 | * issues we may have. |
| 408 | */ |
| 409 | p = select_bad_process(&points); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 410 | |
Christoph Lameter | 9b0f8b0 | 2006-02-20 18:27:52 -0800 | [diff] [blame] | 411 | if (PTR_ERR(p) == -1UL) |
| 412 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | |
Christoph Lameter | 9b0f8b0 | 2006-02-20 18:27:52 -0800 | [diff] [blame] | 414 | /* Found nothing?!?! Either we hang forever, or we panic. */ |
| 415 | if (!p) { |
| 416 | read_unlock(&tasklist_lock); |
| 417 | cpuset_unlock(); |
| 418 | panic("Out of memory and no killable processes...\n"); |
| 419 | } |
| 420 | |
Dave Peterson | 0131592 | 2006-04-18 22:20:44 -0700 | [diff] [blame] | 421 | if (oom_kill_process(p, points, "Out of memory")) |
Christoph Lameter | 9b0f8b0 | 2006-02-20 18:27:52 -0800 | [diff] [blame] | 422 | goto retry; |
| 423 | |
| 424 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 425 | } |
| 426 | |
Christoph Lameter | 9b0f8b0 | 2006-02-20 18:27:52 -0800 | [diff] [blame] | 427 | out: |
Andrew Morton | 140ffce | 2006-03-02 02:54:28 -0800 | [diff] [blame] | 428 | read_unlock(&tasklist_lock); |
Paul Jackson | 505970b | 2006-01-14 13:21:06 -0800 | [diff] [blame] | 429 | cpuset_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | |
| 431 | /* |
| 432 | * Give "p" a good chance of killing itself before we |
Kirill Korotaev | 2f659f4 | 2006-01-08 01:01:05 -0800 | [diff] [blame] | 433 | * retry to allocate memory unless "p" is current |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | */ |
Kirill Korotaev | 2f659f4 | 2006-01-08 01:01:05 -0800 | [diff] [blame] | 435 | if (!test_thread_flag(TIF_MEMDIE)) |
Andrew Morton | 140ffce | 2006-03-02 02:54:28 -0800 | [diff] [blame] | 436 | schedule_timeout_uninterruptible(1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | } |