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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 Jacksona49335c2005-09-06 15:18:09 -07009 * 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 Torvalds1da177e2005-04-16 15:20:36 -070011 *
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
Alexey Dobriyan8ac773b2006-10-19 23:28:32 -070018#include <linux/oom.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/mm.h>
20#include <linux/sched.h>
21#include <linux/swap.h>
22#include <linux/timex.h>
23#include <linux/jiffies.h>
Paul Jacksonef08e3b2005-09-06 15:18:13 -070024#include <linux/cpuset.h>
Martin Schwidefsky8bc719d2006-09-25 23:31:20 -070025#include <linux/module.h>
26#include <linux/notifier.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
KAMEZAWA Hiroyukifadd8fb2006-06-23 02:03:13 -070028int sysctl_panic_on_oom;
Linus Torvalds1da177e2005-04-16 15:20:36 -070029/* #define DEBUG */
30
31/**
Dave Peterson6937a252006-06-23 02:03:13 -070032 * badness - calculate a numeric value for how bad this task has been
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 * @p: task struct of which task we should calculate
Paul Jacksona49335c2005-09-06 15:18:09 -070034 * @uptime: current uptime in seconds
Linus Torvalds1da177e2005-04-16 15:20:36 -070035 *
36 * The formula used is relatively simple and documented inline in the
37 * function. The main rationale is that we want to select a good task
38 * to kill when we run out of memory.
39 *
40 * Good in this context means that:
41 * 1) we lose the minimum amount of work done
42 * 2) we recover a large amount of memory
43 * 3) we don't kill anything innocent of eating tons of memory
44 * 4) we want to kill the minimum amount of processes (one)
45 * 5) we try to kill the process the user expects us to kill, this
46 * algorithm has been meticulously tuned to meet the principle
47 * of least surprise ... (be careful when you change it)
48 */
49
50unsigned long badness(struct task_struct *p, unsigned long uptime)
51{
52 unsigned long points, cpu_time, run_time, s;
Andrew Morton97c2c9b82006-04-18 22:20:38 -070053 struct mm_struct *mm;
54 struct task_struct *child;
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
Andrew Morton97c2c9b82006-04-18 22:20:38 -070056 task_lock(p);
57 mm = p->mm;
58 if (!mm) {
59 task_unlock(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 return 0;
Andrew Morton97c2c9b82006-04-18 22:20:38 -070061 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
63 /*
64 * The memory size of the process is the basis for the badness.
65 */
Andrew Morton97c2c9b82006-04-18 22:20:38 -070066 points = mm->total_vm;
67
68 /*
69 * After this unlock we can no longer dereference local variable `mm'
70 */
71 task_unlock(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73 /*
Hugh Dickins7ba34852007-01-05 16:37:03 -080074 * swapoff can easily use up all memory, so kill those first.
75 */
76 if (p->flags & PF_SWAPOFF)
77 return ULONG_MAX;
78
79 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 * Processes which fork a lot of child processes are likely
Kurt Garloff9827b782006-02-20 18:27:51 -080081 * a good choice. We add half the vmsize of the children if they
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 * have an own mm. This prevents forking servers to flood the
Kurt Garloff9827b782006-02-20 18:27:51 -080083 * machine with an endless amount of children. In case a single
84 * child is eating the vast majority of memory, adding only half
85 * to the parents will make the child our kill candidate of choice.
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 */
Andrew Morton97c2c9b82006-04-18 22:20:38 -070087 list_for_each_entry(child, &p->children, sibling) {
88 task_lock(child);
89 if (child->mm != mm && child->mm)
90 points += child->mm->total_vm/2 + 1;
91 task_unlock(child);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 }
93
94 /*
95 * CPU time is in tens of seconds and run time is in thousands
96 * of seconds. There is no particular reason for this other than
97 * that it turned out to work very well in practice.
98 */
99 cpu_time = (cputime_to_jiffies(p->utime) + cputime_to_jiffies(p->stime))
100 >> (SHIFT_HZ + 3);
101
102 if (uptime >= p->start_time.tv_sec)
103 run_time = (uptime - p->start_time.tv_sec) >> 10;
104 else
105 run_time = 0;
106
107 s = int_sqrt(cpu_time);
108 if (s)
109 points /= s;
110 s = int_sqrt(int_sqrt(run_time));
111 if (s)
112 points /= s;
113
114 /*
115 * Niced processes are most likely less important, so double
116 * their badness points.
117 */
118 if (task_nice(p) > 0)
119 points *= 2;
120
121 /*
122 * Superuser processes are usually more important, so we make it
123 * less likely that we kill those.
124 */
125 if (cap_t(p->cap_effective) & CAP_TO_MASK(CAP_SYS_ADMIN) ||
126 p->uid == 0 || p->euid == 0)
127 points /= 4;
128
129 /*
130 * We don't want to kill a process with direct hardware access.
131 * Not only could that mess up the hardware, but usually users
132 * tend to only have this flag set on applications they think
133 * of as important.
134 */
135 if (cap_t(p->cap_effective) & CAP_TO_MASK(CAP_SYS_RAWIO))
136 points /= 4;
137
138 /*
Nick Piggin7887a3d2006-09-25 23:31:29 -0700139 * If p's nodes don't overlap ours, it may still help to kill p
140 * because p may have allocated or otherwise mapped memory on
141 * this node before. However it will be less likely.
142 */
143 if (!cpuset_excl_nodes_overlap(p))
144 points /= 8;
145
146 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 * Adjust the score by oomkilladj.
148 */
149 if (p->oomkilladj) {
150 if (p->oomkilladj > 0)
151 points <<= p->oomkilladj;
152 else
153 points >>= -(p->oomkilladj);
154 }
155
156#ifdef DEBUG
157 printk(KERN_DEBUG "OOMkill: task %d (%s) got %d points\n",
158 p->pid, p->comm, points);
159#endif
160 return points;
161}
162
163/*
Christoph Lameter9b0f8b02006-02-20 18:27:52 -0800164 * Types of limitations to the nodes from which allocations may occur
165 */
166#define CONSTRAINT_NONE 1
167#define CONSTRAINT_MEMORY_POLICY 2
168#define CONSTRAINT_CPUSET 3
169
170/*
171 * Determine the type of allocation constraint.
172 */
173static inline int constrained_alloc(struct zonelist *zonelist, gfp_t gfp_mask)
174{
175#ifdef CONFIG_NUMA
176 struct zone **z;
KAMEZAWA Hiroyuki96ac5912006-12-29 16:47:20 -0800177 nodemask_t nodes;
178 int node;
Hugh Dickins3d124cb2007-04-23 14:41:02 -0700179
180 nodes_clear(nodes);
KAMEZAWA Hiroyuki96ac5912006-12-29 16:47:20 -0800181 /* node has memory ? */
182 for_each_online_node(node)
183 if (NODE_DATA(node)->node_present_pages)
184 node_set(node, nodes);
Christoph Lameter9b0f8b02006-02-20 18:27:52 -0800185
186 for (z = zonelist->zones; *z; z++)
Paul Jackson02a0e532006-12-13 00:34:25 -0800187 if (cpuset_zone_allowed_softwall(*z, gfp_mask))
Christoph Lameter89fa3022006-09-25 23:31:55 -0700188 node_clear(zone_to_nid(*z), nodes);
Christoph Lameter9b0f8b02006-02-20 18:27:52 -0800189 else
190 return CONSTRAINT_CPUSET;
191
192 if (!nodes_empty(nodes))
193 return CONSTRAINT_MEMORY_POLICY;
194#endif
195
196 return CONSTRAINT_NONE;
197}
198
199/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 * Simple selection loop. We chose the process with the highest
201 * number of 'points'. We expect the caller will lock the tasklist.
202 *
203 * (not docbooked, we don't want this one cluttering up the manual)
204 */
Kurt Garloff9827b782006-02-20 18:27:51 -0800205static struct task_struct *select_bad_process(unsigned long *ppoints)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 struct task_struct *g, *p;
208 struct task_struct *chosen = NULL;
209 struct timespec uptime;
Kurt Garloff9827b782006-02-20 18:27:51 -0800210 *ppoints = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
212 do_posix_clock_monotonic_gettime(&uptime);
Paul Jacksona49335c2005-09-06 15:18:09 -0700213 do_each_thread(g, p) {
214 unsigned long points;
Paul Jacksona49335c2005-09-06 15:18:09 -0700215
Oleg Nesterov28324d12006-09-29 02:01:12 -0700216 /*
217 * skip kernel threads and tasks which have already released
218 * their mm.
219 */
Nick Piggin5081dde2006-09-25 23:31:32 -0700220 if (!p->mm)
221 continue;
Oleg Nesterov28324d12006-09-29 02:01:12 -0700222 /* skip the init task */
223 if (is_init(p))
Paul Jacksona49335c2005-09-06 15:18:09 -0700224 continue;
Paul Jacksonef08e3b2005-09-06 15:18:13 -0700225
Paul Jacksona49335c2005-09-06 15:18:09 -0700226 /*
Nick Pigginb78483a2006-09-29 02:01:14 -0700227 * This task already has access to memory reserves and is
228 * being killed. Don't allow any other task access to the
229 * memory reserve.
230 *
231 * Note: this may have a chance of deadlock if it gets
232 * blocked waiting for another task which itself is waiting
233 * for memory. Is there a better alternative?
234 */
235 if (test_tsk_thread_flag(p, TIF_MEMDIE))
236 return ERR_PTR(-1UL);
237
238 /*
Dave Peterson6937a252006-06-23 02:03:13 -0700239 * This is in the process of releasing memory so wait for it
Paul Jacksona49335c2005-09-06 15:18:09 -0700240 * to finish before killing some other task by mistake.
Nick Piggin50ec3bb2006-09-25 23:31:29 -0700241 *
242 * However, if p is the current task, we allow the 'kill' to
243 * go ahead if it is exiting: this will simply set TIF_MEMDIE,
244 * which will allow it to gain access to memory reserves in
245 * the process of exiting and releasing its resources.
Nick Pigginb78483a2006-09-29 02:01:14 -0700246 * Otherwise we could get an easy OOM deadlock.
Paul Jacksona49335c2005-09-06 15:18:09 -0700247 */
Nick Pigginb78483a2006-09-29 02:01:14 -0700248 if (p->flags & PF_EXITING) {
249 if (p != current)
250 return ERR_PTR(-1UL);
251
Oleg Nesterov972c4ea2006-09-29 02:01:12 -0700252 chosen = p;
253 *ppoints = ULONG_MAX;
Nick Piggin50ec3bb2006-09-25 23:31:29 -0700254 }
Oleg Nesterov972c4ea2006-09-29 02:01:12 -0700255
Nick Piggin4a3ede12006-09-25 23:31:30 -0700256 if (p->oomkilladj == OOM_DISABLE)
257 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258
Paul Jacksona49335c2005-09-06 15:18:09 -0700259 points = badness(p, uptime.tv_sec);
Kurt Garloff9827b782006-02-20 18:27:51 -0800260 if (points > *ppoints || !chosen) {
Paul Jacksona49335c2005-09-06 15:18:09 -0700261 chosen = p;
Kurt Garloff9827b782006-02-20 18:27:51 -0800262 *ppoints = points;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 }
Paul Jacksona49335c2005-09-06 15:18:09 -0700264 } while_each_thread(g, p);
Oleg Nesterov972c4ea2006-09-29 02:01:12 -0700265
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 return chosen;
267}
268
269/**
Ram Gupta5a291b982006-09-25 23:31:54 -0700270 * Send SIGKILL to the selected process irrespective of CAP_SYS_RAW_IO
271 * flag though it's unlikely that we select a process with CAP_SYS_RAW_IO
272 * set.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 */
Nick Pigginf3af38d2006-12-06 20:31:51 -0800274static void __oom_kill_task(struct task_struct *p, int verbose)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275{
Sukadev Bhattiproluf400e192006-09-29 02:00:07 -0700276 if (is_init(p)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 WARN_ON(1);
278 printk(KERN_WARNING "tried to kill init!\n");
279 return;
280 }
281
Oleg Nesterov01017a22006-09-29 02:01:13 -0700282 if (!p->mm) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 WARN_ON(1);
284 printk(KERN_WARNING "tried to kill an mm-less task!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 return;
286 }
Nick Piggin50ec3bb2006-09-25 23:31:29 -0700287
Nick Pigginf3af38d2006-12-06 20:31:51 -0800288 if (verbose)
289 printk(KERN_ERR "Killed process %d (%s)\n", p->pid, p->comm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290
291 /*
292 * We give our sacrificial lamb high priority and access to
293 * all the memory it needs. That way it should be able to
294 * exit() and clear out its resources quickly...
295 */
296 p->time_slice = HZ;
297 set_tsk_thread_flag(p, TIF_MEMDIE);
298
299 force_sig(SIGKILL, p);
300}
301
Nick Pigginf3af38d2006-12-06 20:31:51 -0800302static int oom_kill_task(struct task_struct *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303{
Dave Peterson01315922006-04-18 22:20:44 -0700304 struct mm_struct *mm;
Ingo Molnar36c8b582006-07-03 00:25:41 -0700305 struct task_struct *g, *q;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306
Dave Peterson01315922006-04-18 22:20:44 -0700307 mm = p->mm;
308
309 /* WARNING: mm may not be dereferenced since we did not obtain its
310 * value from get_task_mm(p). This is OK since all we need to do is
311 * compare mm to q->mm below.
312 *
313 * Furthermore, even if mm contains a non-NULL value, p->mm may
314 * change to NULL at any time since we do not hold task_lock(p).
315 * However, this is of no concern to us.
316 */
317
Oleg Nesterov01017a22006-09-29 02:01:13 -0700318 if (mm == NULL)
Dave Peterson01315922006-04-18 22:20:44 -0700319 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320
Nick Pigginc33e0fc2006-12-06 20:31:50 -0800321 /*
322 * Don't kill the process if any threads are set to OOM_DISABLE
323 */
324 do_each_thread(g, q) {
Ankita Garg35ae8342007-03-16 13:38:33 -0800325 if (q->mm == mm && q->oomkilladj == OOM_DISABLE)
Nick Pigginc33e0fc2006-12-06 20:31:50 -0800326 return 1;
327 } while_each_thread(g, q);
328
Nick Pigginf3af38d2006-12-06 20:31:51 -0800329 __oom_kill_task(p, 1);
Nick Pigginc33e0fc2006-12-06 20:31:50 -0800330
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 /*
332 * kill all processes that share the ->mm (i.e. all threads),
Nick Pigginf2a2a712006-12-06 20:31:52 -0800333 * but are in a different thread group. Don't let them have access
334 * to memory reserves though, otherwise we might deplete all memory.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 */
Nick Pigginc33e0fc2006-12-06 20:31:50 -0800336 do_each_thread(g, q) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 if (q->mm == mm && q->tgid != p->tgid)
David Rientjes650a7c92007-04-23 21:36:13 -0700338 force_sig(SIGKILL, q);
Nick Pigginc33e0fc2006-12-06 20:31:50 -0800339 } while_each_thread(g, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340
Dave Peterson01315922006-04-18 22:20:44 -0700341 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342}
343
Dave Peterson01315922006-04-18 22:20:44 -0700344static int oom_kill_process(struct task_struct *p, unsigned long points,
345 const char *message)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 struct task_struct *c;
348 struct list_head *tsk;
349
Nick Piggin50ec3bb2006-09-25 23:31:29 -0700350 /*
351 * If the task is already exiting, don't alarm the sysadmin or kill
352 * its children or threads, just set TIF_MEMDIE so it can die quickly
353 */
354 if (p->flags & PF_EXITING) {
Nick Pigginf3af38d2006-12-06 20:31:51 -0800355 __oom_kill_task(p, 0);
Nick Piggin50ec3bb2006-09-25 23:31:29 -0700356 return 0;
357 }
358
Nick Pigginf3af38d2006-12-06 20:31:51 -0800359 printk(KERN_ERR "%s: kill process %d (%s) score %li or a child\n",
360 message, p->pid, p->comm, points);
361
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 /* Try to kill a child first */
363 list_for_each(tsk, &p->children) {
364 c = list_entry(tsk, struct task_struct, sibling);
365 if (c->mm == p->mm)
366 continue;
Nick Pigginf3af38d2006-12-06 20:31:51 -0800367 if (!oom_kill_task(c))
Dave Peterson01315922006-04-18 22:20:44 -0700368 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 }
Nick Pigginf3af38d2006-12-06 20:31:51 -0800370 return oom_kill_task(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371}
372
Martin Schwidefsky8bc719d2006-09-25 23:31:20 -0700373static BLOCKING_NOTIFIER_HEAD(oom_notify_list);
374
375int register_oom_notifier(struct notifier_block *nb)
376{
377 return blocking_notifier_chain_register(&oom_notify_list, nb);
378}
379EXPORT_SYMBOL_GPL(register_oom_notifier);
380
381int unregister_oom_notifier(struct notifier_block *nb)
382{
383 return blocking_notifier_chain_unregister(&oom_notify_list, nb);
384}
385EXPORT_SYMBOL_GPL(unregister_oom_notifier);
386
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387/**
Dave Peterson6937a252006-06-23 02:03:13 -0700388 * out_of_memory - kill the "best" process when we run out of memory
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 *
390 * If we run out of memory, we have the choice between either
391 * killing a random task (bad), letting the system crash (worse)
392 * OR try to be smart about which process to kill. Note that we
393 * don't have to be perfect here, we just have to be good.
394 */
Christoph Lameter9b0f8b02006-02-20 18:27:52 -0800395void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396{
Ingo Molnar36c8b582006-07-03 00:25:41 -0700397 struct task_struct *p;
Andrew Mortond6713e02006-02-28 16:59:19 -0800398 unsigned long points = 0;
Martin Schwidefsky8bc719d2006-09-25 23:31:20 -0700399 unsigned long freed = 0;
400
401 blocking_notifier_call_chain(&oom_notify_list, 0, &freed);
402 if (freed > 0)
403 /* Got some memory back in the last second. */
404 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405
Anton Blanchard42639262005-07-07 17:56:06 -0700406 if (printk_ratelimit()) {
Nick Pigginb72f1602006-09-25 23:31:32 -0700407 printk(KERN_WARNING "%s invoked oom-killer: "
408 "gfp_mask=0x%x, order=%d, oomkilladj=%d\n",
409 current->comm, gfp_mask, order, current->oomkilladj);
Andrew Mortonb958f7d2006-02-01 03:05:51 -0800410 dump_stack();
Anton Blanchard42639262005-07-07 17:56:06 -0700411 show_mem();
412 }
Janet Morgan578c2fd2005-06-21 17:14:56 -0700413
Paul Jackson505970b2006-01-14 13:21:06 -0800414 cpuset_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 read_lock(&tasklist_lock);
Christoph Lameter9b0f8b02006-02-20 18:27:52 -0800416
417 /*
418 * Check if there were limitations on the allocation (only relevant for
419 * NUMA) that may require different handling.
420 */
421 switch (constrained_alloc(zonelist, gfp_mask)) {
422 case CONSTRAINT_MEMORY_POLICY:
Dave Peterson01315922006-04-18 22:20:44 -0700423 oom_kill_process(current, points,
Christoph Lameter9b0f8b02006-02-20 18:27:52 -0800424 "No available memory (MPOL_BIND)");
425 break;
426
427 case CONSTRAINT_CPUSET:
Dave Peterson01315922006-04-18 22:20:44 -0700428 oom_kill_process(current, points,
Christoph Lameter9b0f8b02006-02-20 18:27:52 -0800429 "No available memory in cpuset");
430 break;
431
432 case CONSTRAINT_NONE:
KAMEZAWA Hiroyukifadd8fb2006-06-23 02:03:13 -0700433 if (sysctl_panic_on_oom)
434 panic("out of memory. panic_on_oom is selected\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435retry:
Christoph Lameter9b0f8b02006-02-20 18:27:52 -0800436 /*
437 * Rambo mode: Shoot down a process and hope it solves whatever
438 * issues we may have.
439 */
440 p = select_bad_process(&points);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441
Christoph Lameter9b0f8b02006-02-20 18:27:52 -0800442 if (PTR_ERR(p) == -1UL)
443 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444
Christoph Lameter9b0f8b02006-02-20 18:27:52 -0800445 /* Found nothing?!?! Either we hang forever, or we panic. */
446 if (!p) {
447 read_unlock(&tasklist_lock);
448 cpuset_unlock();
449 panic("Out of memory and no killable processes...\n");
450 }
451
Dave Peterson01315922006-04-18 22:20:44 -0700452 if (oom_kill_process(p, points, "Out of memory"))
Christoph Lameter9b0f8b02006-02-20 18:27:52 -0800453 goto retry;
454
455 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 }
457
Christoph Lameter9b0f8b02006-02-20 18:27:52 -0800458out:
Andrew Morton140ffce2006-03-02 02:54:28 -0800459 read_unlock(&tasklist_lock);
Paul Jackson505970b2006-01-14 13:21:06 -0800460 cpuset_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461
462 /*
463 * Give "p" a good chance of killing itself before we
Kirill Korotaev2f659f42006-01-08 01:01:05 -0800464 * retry to allocate memory unless "p" is current
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 */
Kirill Korotaev2f659f42006-01-08 01:01:05 -0800466 if (!test_thread_flag(TIF_MEMDIE))
Andrew Morton140ffce2006-03-02 02:54:28 -0800467 schedule_timeout_uninterruptible(1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468}