}
#endif
+enum oom_scan_t oom_scan_process_thread(struct task_struct *task,
+ unsigned long totalpages, const nodemask_t *nodemask,
+ bool force_kill)
+{
+ if (task->exit_state)
+ return OOM_SCAN_CONTINUE;
+ if (oom_unkillable_task(task, NULL, nodemask))
+ return OOM_SCAN_CONTINUE;
+
+ /*
+ * This task already has access to memory reserves and is being killed.
+ * Don't allow any other task to have access to the reserves.
+ */
+ if (test_tsk_thread_flag(task, TIF_MEMDIE)) {
+ if (unlikely(frozen(task)))
+ __thaw_task(task);
+ if (!force_kill)
+ return OOM_SCAN_ABORT;
+ }
+ if (!task->mm)
+ return OOM_SCAN_CONTINUE;
+
+ if (task->flags & PF_EXITING) {
+ /*
+ * If task is current and is in the process of releasing memory,
+ * allow the "kill" to set TIF_MEMDIE, which will allow it to
+ * access memory reserves. Otherwise, it may stall forever.
+ *
+ * The iteration isn't broken here, however, in case other
+ * threads are found to have already been oom killed.
+ */
+ if (task == current)
+ return OOM_SCAN_SELECT;
+ else if (!force_kill) {
+ /*
+ * If this task is not being ptraced on exit, then wait
+ * for it to finish before killing some other task
+ * unnecessarily.
+ */
+ if (!(task->group_leader->ptrace & PT_TRACE_EXIT))
+ return OOM_SCAN_ABORT;
+ }
+ }
+ return OOM_SCAN_OK;
+}
+
/*
* Simple selection loop. We chose the process with the highest
- * number of 'points'. We expect the caller will lock the tasklist.
+ * number of 'points'.
*
* (not docbooked, we don't want this one cluttering up the manual)
*/
static struct task_struct *select_bad_process(unsigned int *ppoints,
- unsigned long totalpages, struct mem_cgroup *memcg,
- const nodemask_t *nodemask, bool force_kill)
+ unsigned long totalpages, const nodemask_t *nodemask,
+ bool force_kill)
{
struct task_struct *g, *p;
struct task_struct *chosen = NULL;
unsigned long chosen_points = 0;
+ rcu_read_lock();
do_each_thread(g, p) {
unsigned int points;
- if (p->exit_state)
- continue;
- if (oom_unkillable_task(p, memcg, nodemask))
- continue;
-
- /*
- * This task already has access to memory reserves and is
- * being killed. Don't allow any other task access to the
- * memory reserve.
- *
- * Note: this may have a chance of deadlock if it gets
- * blocked waiting for another task which itself is waiting
- * for memory. Is there a better alternative?
- */
- if (test_tsk_thread_flag(p, TIF_MEMDIE)) {
- if (unlikely(frozen(p)))
- __thaw_task(p);
- if (!force_kill)
- return ERR_PTR(-1UL);
- }
- if (!p->mm)
+ switch (oom_scan_process_thread(p, totalpages, nodemask,
+ force_kill)) {
+ case OOM_SCAN_SELECT:
+ chosen = p;
+ chosen_points = ULONG_MAX;
+ /* fall through */
+ case OOM_SCAN_CONTINUE:
continue;
-
- if (p->flags & PF_EXITING) {
- /*
- * If p is the current task and is in the process of
- * releasing memory, we allow the "kill" to set
- * TIF_MEMDIE, which will allow it to gain access to
- * memory reserves. Otherwise, it may stall forever.
- *
- * The loop isn't broken here, however, in case other
- * threads are found to have already been oom killed.
- */
- if (p == current) {
- chosen = p;
- chosen_points = ULONG_MAX;
- } else if (!force_kill) {
- /*
- * If this task is not being ptraced on exit,
- * then wait for it to finish before killing
- * some other task unnecessarily.
- */
- if (!(p->group_leader->ptrace & PT_TRACE_EXIT))
- return ERR_PTR(-1UL);
- }
- }
-
- points = oom_badness(p, memcg, nodemask, totalpages);
+ case OOM_SCAN_ABORT:
+ rcu_read_unlock();
+ return ERR_PTR(-1UL);
+ case OOM_SCAN_OK:
+ break;
+ };
+ points = oom_badness(p, NULL, nodemask, totalpages);
if (points > chosen_points) {
chosen = p;
chosen_points = points;
}
} while_each_thread(g, p);
+ if (chosen)
+ get_task_struct(chosen);
+ rcu_read_unlock();
*ppoints = chosen_points * 1000 / totalpages;
return chosen;
* 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.
- *
- * Call with tasklist_lock read-locked.
+ * State information includes task's pid, uid, tgid, vm size, rss, nr_ptes,
+ * swapents, oom_score_adj value, and name.
*/
static void dump_tasks(const struct mem_cgroup *memcg, 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");
+ pr_info("[ pid ] uid tgid total_vm rss nr_ptes swapents oom_score_adj name\n");
+ rcu_read_lock();
for_each_process(p) {
if (oom_unkillable_task(p, memcg, nodemask))
continue;
continue;
}
- pr_info("[%5d] %5d %5d %8lu %8lu %3u %3d %5d %s\n",
+ pr_info("[%5d] %5d %5d %8lu %8lu %7lu %8lu %5d %s\n",
task->pid, from_kuid(&init_user_ns, task_uid(task)),
task->tgid, task->mm->total_vm, get_mm_rss(task->mm),
- task_cpu(task), task->signal->oom_adj,
+ task->mm->nr_ptes,
+ get_mm_counter(task->mm, MM_SWAPENTS),
task->signal->oom_score_adj, task->comm);
task_unlock(task);
}
+ rcu_read_unlock();
}
static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order,
}
#define K(x) ((x) << (PAGE_SHIFT-10))
-static void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
- unsigned int points, unsigned long totalpages,
- struct mem_cgroup *memcg, nodemask_t *nodemask,
- const char *message)
+/*
+ * Must be called while holding a reference to p, which will be released upon
+ * returning.
+ */
+void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
+ unsigned int points, unsigned long totalpages,
+ struct mem_cgroup *memcg, nodemask_t *nodemask,
+ const char *message)
{
struct task_struct *victim = p;
struct task_struct *child;
*/
if (p->flags & PF_EXITING) {
set_tsk_thread_flag(p, TIF_MEMDIE);
+ put_task_struct(p);
return;
}
* parent. This attempts to lose the minimal amount of work done while
* still freeing memory.
*/
+ read_lock(&tasklist_lock);
do {
list_for_each_entry(child, &t->children, sibling) {
unsigned int child_points;
child_points = oom_badness(child, memcg, nodemask,
totalpages);
if (child_points > victim_points) {
+ put_task_struct(victim);
victim = child;
victim_points = child_points;
+ get_task_struct(victim);
}
}
} while_each_thread(p, t);
+ read_unlock(&tasklist_lock);
- victim = find_lock_task_mm(victim);
- if (!victim)
+ rcu_read_lock();
+ p = find_lock_task_mm(victim);
+ if (!p) {
+ rcu_read_unlock();
+ put_task_struct(victim);
return;
+ } else if (victim != p) {
+ get_task_struct(p);
+ put_task_struct(victim);
+ victim = p;
+ }
/* mm cannot safely be dereferenced after task_unlock(victim) */
mm = victim->mm;
task_unlock(p);
do_send_sig_info(SIGKILL, SEND_SIG_FORCED, p, true);
}
+ rcu_read_unlock();
set_tsk_thread_flag(victim, TIF_MEMDIE);
do_send_sig_info(SIGKILL, SEND_SIG_FORCED, victim, true);
+ put_task_struct(victim);
}
#undef K
/*
* 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, const nodemask_t *nodemask)
+void check_panic_on_oom(enum oom_constraint constraint, gfp_t gfp_mask,
+ int order, const nodemask_t *nodemask)
{
if (likely(!sysctl_panic_on_oom))
return;
if (constraint != CONSTRAINT_NONE)
return;
}
- read_lock(&tasklist_lock);
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");
}
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR
-void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
- int order)
-{
- unsigned long limit;
- unsigned int points = 0;
- struct task_struct *p;
-
- /*
- * If current has a pending SIGKILL, then automatically select it. The
- * goal is to allow it to allocate so that it may quickly exit and free
- * its memory.
- */
- if (fatal_signal_pending(current)) {
- set_thread_flag(TIF_MEMDIE);
- return;
- }
-
- check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL);
- limit = mem_cgroup_get_limit(memcg) >> PAGE_SHIFT ? : 1;
- read_lock(&tasklist_lock);
- p = select_bad_process(&points, limit, memcg, NULL, false);
- if (p && PTR_ERR(p) != -1UL)
- oom_kill_process(p, gfp_mask, order, points, limit, memcg, NULL,
- "Memory cgroup out of memory");
- read_unlock(&tasklist_lock);
-}
-#endif
-
static BLOCKING_NOTIFIER_HEAD(oom_notify_list);
int register_oom_notifier(struct notifier_block *nb)
struct task_struct *p;
unsigned long totalpages;
unsigned long freed = 0;
- unsigned int points;
+ unsigned int uninitialized_var(points);
enum oom_constraint constraint = CONSTRAINT_NONE;
int killed = 0;
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 &&
+ if (sysctl_oom_kill_allocating_task && current->mm &&
!oom_unkillable_task(current, NULL, nodemask) &&
- current->mm) {
+ current->signal->oom_score_adj != OOM_SCORE_ADJ_MIN) {
+ get_task_struct(current);
oom_kill_process(current, gfp_mask, order, 0, totalpages, NULL,
nodemask,
"Out of memory (oom_kill_allocating_task)");
goto out;
}
- p = select_bad_process(&points, totalpages, NULL, mpol_mask,
- force_kill);
+ p = select_bad_process(&points, totalpages, mpol_mask, force_kill);
/* Found nothing?!?! Either we hang forever, or we panic. */
if (!p) {
dump_header(NULL, gfp_mask, order, NULL, mpol_mask);
- read_unlock(&tasklist_lock);
panic("Out of memory and no killable processes...\n");
}
if (PTR_ERR(p) != -1UL) {
killed = 1;
}
out:
- read_unlock(&tasklist_lock);
-
/*
- * Give "p" a good chance of killing itself before we
- * retry to allocate memory unless "p" is current
+ * Give the killed threads a good chance of exiting before trying to
+ * allocate memory again.
*/
- if (killed && !test_thread_flag(TIF_MEMDIE))
- schedule_timeout_uninterruptible(1);
+ if (killed)
+ schedule_timeout_killable(1);
}
/*
out_of_memory(NULL, 0, 0, NULL, false);
clear_system_oom();
}
- if (!test_thread_flag(TIF_MEMDIE))
- schedule_timeout_uninterruptible(1);
+ schedule_timeout_killable(1);
}
projects / karo-tx-linux.git / blobdiff