#include <linux/jiffies.h>
#include <linux/cpuset.h>
-int sysctl_panic_on_oom;
/* #define DEBUG */
/**
- * badness - calculate a numeric value for how bad this task has been
+ * oom_badness - calculate a numeric value for how bad this task has been
* @p: task struct of which task we should calculate
* @uptime: current uptime in seconds
*
unsigned long badness(struct task_struct *p, unsigned long uptime)
{
unsigned long points, cpu_time, run_time, s;
- struct mm_struct *mm;
- struct task_struct *child;
+ struct list_head *tsk;
- task_lock(p);
- mm = p->mm;
- if (!mm) {
- task_unlock(p);
+ if (!p->mm)
return 0;
- }
-
- /*
- * swapoff can easily use up all memory, so kill those first.
- */
- if (p->flags & PF_SWAPOFF)
- return ULONG_MAX;
/*
* The memory size of the process is the basis for the badness.
*/
- points = mm->total_vm;
-
- /*
- * After this unlock we can no longer dereference local variable `mm'
- */
- task_unlock(p);
-
+ points = p->mm->total_vm;
/* FIXME: add vserver badness ;) */
/*
* child is eating the vast majority of memory, adding only half
* to the parents will make the child our kill candidate of choice.
*/
- list_for_each_entry(child, &p->children, sibling) {
- task_lock(child);
- if (child->mm != mm && child->mm)
- points += child->mm->total_vm/2 + 1;
- task_unlock(child);
+ list_for_each(tsk, &p->children) {
+ struct task_struct *chld;
+ chld = list_entry(tsk, struct task_struct, sibling);
+ if (chld->mm != p->mm && chld->mm)
+ points += chld->mm->total_vm/2 + 1;
}
/*
if (cap_t(p->cap_effective) & CAP_TO_MASK(CAP_SYS_RAWIO))
points /= 4;
- /*
- * If p's nodes don't overlap ours, it may still help to kill p
- * because p may have allocated or otherwise mapped memory on
- * this node before. However it will be less likely.
- */
- if (!cpuset_excl_nodes_overlap(p))
- points /= 8;
-
/*
* Adjust the score by oomkilladj.
*/
unsigned long points;
int releasing;
- /* skip kernel threads */
- if (!p->mm)
- continue;
-
/* skip the init task with pid == 1 */
if (p->pid == 1)
continue;
+ if (p->oomkilladj == OOM_DISABLE)
+ continue;
+ /* If p's nodes don't overlap ours, it won't help to kill p. */
+ if (!cpuset_excl_nodes_overlap(p))
+ continue;
+
/*
- * This is in the process of releasing memory so wait for it
+ * This is in the process of releasing memory so for wait it
* to finish before killing some other task by mistake.
- *
- * However, if p is the current task, we allow the 'kill' to
- * go ahead if it is exiting: this will simply set TIF_MEMDIE,
- * which will allow it to gain access to memory reserves in
- * the process of exiting and releasing its resources.
- * Otherwise we could get an OOM deadlock.
*/
releasing = test_tsk_thread_flag(p, TIF_MEMDIE) ||
p->flags & PF_EXITING;
- if (releasing) {
- /* PF_DEAD tasks have already released their mm */
- if (p->flags & PF_DEAD)
- continue;
- if (p->flags & PF_EXITING && p == current) {
- chosen = p;
- *ppoints = ULONG_MAX;
- break;
- }
+ if (releasing && !(p->flags & PF_DEAD))
return ERR_PTR(-1UL);
- }
- if (p->oomkilladj == OOM_DISABLE)
- continue;
+ if (p->flags & PF_SWAPOFF)
+ return p;
points = badness(p, uptime.tv_sec);
if (points > *ppoints || !chosen) {
* CAP_SYS_RAW_IO set, send SIGTERM instead (but it's unlikely that
* we select a process with CAP_SYS_RAW_IO set).
*/
-static void __oom_kill_task(struct task_struct *p, const char *message)
+static void __oom_kill_task(task_t *p, const char *message)
{
if (p->pid == 1) {
WARN_ON(1);
return;
}
task_unlock(p);
- if (message)
- printk(KERN_ERR "%s: Killed process %d (%s).\n",
+ printk(KERN_ERR "%s: Killed process %d (%s).\n",
message, p->pid, p->comm);
/*
force_sig(SIGKILL, p);
}
-static int oom_kill_task(struct task_struct *p, const char *message)
+static struct mm_struct *oom_kill_task(task_t *p, const char *message)
{
- struct mm_struct *mm;
- struct task_struct *g, *q;
-
- mm = p->mm;
-
- /* WARNING: mm may not be dereferenced since we did not obtain its
- * value from get_task_mm(p). This is OK since all we need to do is
- * compare mm to q->mm below.
- *
- * Furthermore, even if mm contains a non-NULL value, p->mm may
- * change to NULL at any time since we do not hold task_lock(p).
- * However, this is of no concern to us.
- */
-
- if (mm == NULL || mm == &init_mm)
- return 1;
+ struct mm_struct *mm = get_task_mm(p);
+ task_t * g, * q;
+
+ if (!mm)
+ return NULL;
+ if (mm == &init_mm) {
+ mmput(mm);
+ return NULL;
+ }
__oom_kill_task(p, message);
/*
__oom_kill_task(q, message);
while_each_thread(g, q);
- return 0;
+ return mm;
}
-static int oom_kill_process(struct task_struct *p, unsigned long points,
- const char *message)
+static struct mm_struct *oom_kill_process(struct task_struct *p,
+ unsigned long points, const char *message)
{
+ struct mm_struct *mm;
struct task_struct *c;
struct list_head *tsk;
- /*
- * If the task is already exiting, don't alarm the sysadmin or kill
- * its children or threads, just set TIF_MEMDIE so it can die quickly
- */
- if (p->flags & PF_EXITING) {
- __oom_kill_task(p, NULL);
- return 0;
- }
-
+ printk(KERN_ERR "Out of Memory: Kill process %d (%s) score %li and "
+ "children.\n", p->pid, p->comm, points);
/* Try to kill a child first */
list_for_each(tsk, &p->children) {
c = list_entry(tsk, struct task_struct, sibling);
if (c->mm == p->mm)
continue;
- if (!oom_kill_task(c, message))
- return 0;
+ mm = oom_kill_task(c, message);
+ if (mm)
+ return mm;
}
return oom_kill_task(p, message);
}
-int should_oom_kill(void)
-{
- static spinlock_t oom_lock = SPIN_LOCK_UNLOCKED;
- static unsigned long first, last, count, lastkill;
- unsigned long now, since;
- int ret = 0;
-
- spin_lock(&oom_lock);
- now = jiffies;
- since = now - last;
- last = now;
-
- /*
- * If it's been a long time since last failure,
- * we're not oom.
- */
- if (since > 5*HZ)
- goto reset;
-
- /*
- * If we haven't tried for at least one second,
- * we're not really oom.
- */
- since = now - first;
- if (since < HZ)
- goto out_unlock;
-
- /*
- * If we have gotten only a few failures,
- * we're not really oom.
- */
- if (++count < 10)
- goto out_unlock;
-
- /*
- * If we just killed a process, wait a while
- * to give that task a chance to exit. This
- * avoids killing multiple processes needlessly.
- */
- since = now - lastkill;
- if (since < HZ*5)
- goto out_unlock;
-
- /*
- * Ok, really out of memory. Kill something.
- */
- lastkill = now;
- ret = 1;
-
-reset:
-/*
- * We dropped the lock above, so check to be sure the variable
- * first only ever increases to prevent false OOM's.
- */
- if (time_after(now, first))
- first = now;
- count = 0;
-
-out_unlock:
- spin_unlock(&oom_lock);
- return ret;
-}
-
/**
- * out_of_memory - kill the "best" process when we run out of memory
+ * oom_kill - kill the "best" process when we run out of memory
*
* If we run out of memory, we have the choice between either
* killing a random task (bad), letting the system crash (worse)
*/
void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
{
- struct task_struct *p;
+ struct mm_struct *mm = NULL;
+ task_t *p;
unsigned long points = 0;
if (printk_ratelimit()) {
- printk(KERN_WARNING "%s invoked oom-killer: "
- "gfp_mask=0x%x, order=%d, oomkilladj=%d\n",
- current->comm, gfp_mask, order, current->oomkilladj);
+ printk("oom-killer: gfp_mask=0x%x, order=%d\n",
+ gfp_mask, order);
dump_stack();
show_mem();
}
- if (!should_oom_kill())
- return;
-
cpuset_lock();
read_lock(&tasklist_lock);
*/
switch (constrained_alloc(zonelist, gfp_mask)) {
case CONSTRAINT_MEMORY_POLICY:
- oom_kill_process(current, points,
+ mm = oom_kill_process(current, points,
"No available memory (MPOL_BIND)");
break;
case CONSTRAINT_CPUSET:
- oom_kill_process(current, points,
+ mm = oom_kill_process(current, points,
"No available memory in cpuset");
break;
case CONSTRAINT_NONE:
- if (sysctl_panic_on_oom)
- panic("out of memory. panic_on_oom is selected\n");
retry:
/*
* Rambo mode: Shoot down a process and hope it solves whatever
panic("Out of memory and no killable processes...\n");
}
- if (oom_kill_process(p, points, "Out of memory"))
+ mm = oom_kill_process(p, points, "Out of memory");
+ if (!mm)
goto retry;
break;
out:
read_unlock(&tasklist_lock);
cpuset_unlock();
+ if (mm)
+ mmput(mm);
/*
* Give "p" a good chance of killing itself before we
git://git.onelab.eu / linux-2.6.git / blobdiff