}
/* return true if the task is not adequate as candidate victim task. */
-static bool oom_unkillable_task(struct task_struct *p, struct mem_cgroup *mem,
- const nodemask_t *nodemask)
+static bool oom_unkillable_task(struct task_struct *p,
+ const struct mem_cgroup *mem, const nodemask_t *nodemask)
{
if (is_global_init(p))
return true;
return 0;
/*
- * Shortcut check for OOM_SCORE_ADJ_MIN so the entire heuristic doesn't
- * need to be executed for something that cannot be killed.
+ * Shortcut check for a thread sharing p->mm that is OOM_SCORE_ADJ_MIN
+ * so the entire heuristic doesn't need to be executed for something
+ * that cannot be killed.
*/
- if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) {
+ if (atomic_read(&p->mm->oom_disable_count)) {
task_unlock(p);
return 0;
}
*/
points += p->signal->oom_score_adj;
- if (points < 0)
- return 0;
+ /*
+ * Never return 0 for an eligible task that may be killed since it's
+ * possible that no single user task uses more than 0.1% of memory and
+ * no single admin tasks uses more than 3.0%.
+ */
+ if (points <= 0)
+ return 1;
return (points < 1000) ? points : 1000;
}
/**
* dump_tasks - dump current memory state of all system tasks
* @mem: current's memory controller, if constrained
+ * @nodemask: nodemask passed to page allocator for mempolicy ooms
*
- * Dumps the current memory state of all system tasks, excluding kernel threads.
+ * Dumps the current memory state of all eligible tasks. Tasks not in the same
+ * memcg, not in the same cpuset, or bound to a disjoint set of mempolicy nodes
+ * are not shown.
* State information includes task's pid, uid, tgid, vm size, rss, cpu, oom_adj
* value, oom_score_adj value, and name.
*
- * If the actual is non-NULL, only tasks that are a member of the mem_cgroup are
- * shown.
- *
* Call with tasklist_lock read-locked.
*/
-static void dump_tasks(const struct mem_cgroup *mem)
+static void dump_tasks(const struct mem_cgroup *mem, const nodemask_t *nodemask)
{
struct task_struct *p;
struct task_struct *task;
pr_info("[ pid ] uid tgid total_vm rss cpu oom_adj oom_score_adj name\n");
for_each_process(p) {
- if (p->flags & PF_KTHREAD)
- continue;
- if (mem && !task_in_mem_cgroup(p, mem))
+ if (oom_unkillable_task(p, mem, nodemask))
continue;
task = find_lock_task_mm(p);
}
static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order,
- struct mem_cgroup *mem)
+ struct mem_cgroup *mem, const nodemask_t *nodemask)
{
task_lock(current);
pr_warning("%s invoked oom-killer: gfp_mask=0x%x, order=%d, "
mem_cgroup_print_oom_info(mem, p);
show_mem();
if (sysctl_oom_dump_tasks)
- dump_tasks(mem);
+ dump_tasks(mem, nodemask);
}
#define K(x) ((x) << (PAGE_SHIFT-10))
static int oom_kill_task(struct task_struct *p, struct mem_cgroup *mem)
{
+ struct task_struct *q;
+ struct mm_struct *mm;
+
p = find_lock_task_mm(p);
if (!p)
return 1;
+ /* mm cannot be safely dereferenced after task_unlock(p) */
+ mm = p->mm;
+
pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB\n",
task_pid_nr(p), p->comm, K(p->mm->total_vm),
K(get_mm_counter(p->mm, MM_ANONPAGES)),
K(get_mm_counter(p->mm, MM_FILEPAGES)));
task_unlock(p);
+ /*
+ * Kill all processes sharing p->mm in other thread groups, if any.
+ * They don't get access to memory reserves or a higher scheduler
+ * priority, though, to avoid depletion of all memory or task
+ * starvation. This prevents mm->mmap_sem livelock when an oom killed
+ * task cannot exit because it requires the semaphore and its contended
+ * by another thread trying to allocate memory itself. That thread will
+ * now get access to memory reserves since it has a pending fatal
+ * signal.
+ */
+ for_each_process(q)
+ if (q->mm == mm && !same_thread_group(q, p)) {
+ task_lock(q); /* Protect ->comm from prctl() */
+ pr_err("Kill process %d (%s) sharing same memory\n",
+ task_pid_nr(q), q->comm);
+ task_unlock(q);
+ force_sig(SIGKILL, q);
+ }
set_tsk_thread_flag(p, TIF_MEMDIE);
force_sig(SIGKILL, p);
unsigned int victim_points = 0;
if (printk_ratelimit())
- dump_header(p, gfp_mask, order, mem);
+ dump_header(p, gfp_mask, order, mem, nodemask);
/*
* If the task is already exiting, don't alarm the sysadmin or kill
* Determines whether the kernel must panic because of the panic_on_oom sysctl.
*/
static void check_panic_on_oom(enum oom_constraint constraint, gfp_t gfp_mask,
- int order)
+ int order, const nodemask_t *nodemask)
{
if (likely(!sysctl_panic_on_oom))
return;
return;
}
read_lock(&tasklist_lock);
- dump_header(NULL, gfp_mask, order, NULL);
+ dump_header(NULL, gfp_mask, order, NULL, nodemask);
read_unlock(&tasklist_lock);
panic("Out of memory: %s panic_on_oom is enabled\n",
sysctl_panic_on_oom == 2 ? "compulsory" : "system-wide");
unsigned int points = 0;
struct task_struct *p;
- check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, 0);
+ check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, 0, NULL);
limit = mem_cgroup_get_limit(mem) >> PAGE_SHIFT;
read_lock(&tasklist_lock);
retry:
void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,
int order, nodemask_t *nodemask)
{
+ const nodemask_t *mpol_mask;
struct task_struct *p;
unsigned long totalpages;
unsigned long freed = 0;
*/
constraint = constrained_alloc(zonelist, gfp_mask, nodemask,
&totalpages);
- check_panic_on_oom(constraint, gfp_mask, order);
+ mpol_mask = (constraint == CONSTRAINT_MEMORY_POLICY) ? nodemask : NULL;
+ check_panic_on_oom(constraint, gfp_mask, order, mpol_mask);
read_lock(&tasklist_lock);
if (sysctl_oom_kill_allocating_task &&
!oom_unkillable_task(current, NULL, nodemask) &&
- (current->signal->oom_adj != OOM_DISABLE)) {
+ current->mm && !atomic_read(¤t->mm->oom_disable_count)) {
/*
* oom_kill_process() needs tasklist_lock held. If it returns
* non-zero, current could not be killed so we must fallback to
}
retry:
- p = select_bad_process(&points, totalpages, NULL,
- constraint == CONSTRAINT_MEMORY_POLICY ? nodemask :
- NULL);
+ p = select_bad_process(&points, totalpages, NULL, mpol_mask);
if (PTR_ERR(p) == -1UL)
goto out;
/* Found nothing?!?! Either we hang forever, or we panic. */
if (!p) {
- dump_header(NULL, gfp_mask, order, NULL);
+ dump_header(NULL, gfp_mask, order, NULL, mpol_mask);
read_unlock(&tasklist_lock);
panic("Out of memory and no killable processes...\n");
}
git://bbs.cooldavid.org / net-next-2.6.git / blobdiff