#include <linux/ptrace.h>
#include <linux/freezer.h>
#include <linux/ftrace.h>
+#include <linux/ratelimit.h>
#define CREATE_TRACE_POINTS
#include <trace/events/oom.h>
*/
static struct task_struct *select_bad_process(unsigned int *ppoints,
unsigned long totalpages, struct mem_cgroup *memcg,
- const nodemask_t *nodemask)
+ const nodemask_t *nodemask, bool force_kill)
{
struct task_struct *g, *p;
struct task_struct *chosen = NULL;
if (test_tsk_thread_flag(p, TIF_MEMDIE)) {
if (unlikely(frozen(p)))
__thaw_task(p);
- return ERR_PTR(-1UL);
+ if (!force_kill)
+ return ERR_PTR(-1UL);
}
if (!p->mm)
continue;
if (p == current) {
chosen = p;
*ppoints = 1000;
- } else {
+ } else if (!force_kill) {
/*
* If this task is not being ptraced on exit,
* then wait for it to finish before killing
}
#define K(x) ((x) << (PAGE_SHIFT-10))
-static void oom_kill_task(struct task_struct *p)
-{
- struct task_struct *q;
- struct mm_struct *mm;
-
- p = find_lock_task_mm(p);
- if (!p)
- return;
-
- /* 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 user 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) &&
- !(q->flags & PF_KTHREAD)) {
- if (q->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
- continue;
-
- 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);
-}
-#undef K
-
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,
struct task_struct *victim = p;
struct task_struct *child;
struct task_struct *t = p;
+ struct mm_struct *mm;
unsigned int victim_points = 0;
-
- if (printk_ratelimit())
- dump_header(p, gfp_mask, order, memcg, nodemask);
+ static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
/*
* If the task is already exiting, don't alarm the sysadmin or kill
return;
}
+ if (__ratelimit(&oom_rs))
+ dump_header(p, gfp_mask, order, memcg, nodemask);
+
task_lock(p);
pr_err("%s: Kill process %d (%s) score %d or sacrifice child\n",
message, task_pid_nr(p), p->comm, points);
}
} while_each_thread(p, t);
- oom_kill_task(victim);
+ victim = find_lock_task_mm(victim);
+ if (!victim)
+ return;
+
+ /* mm cannot safely be dereferenced after task_unlock(victim) */
+ mm = victim->mm;
+ pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB\n",
+ task_pid_nr(victim), victim->comm, K(victim->mm->total_vm),
+ K(get_mm_counter(victim->mm, MM_ANONPAGES)),
+ K(get_mm_counter(victim->mm, MM_FILEPAGES)));
+ task_unlock(victim);
+
+ /*
+ * Kill all user processes sharing victim->mm in other thread groups, if
+ * any. They don't get access to memory reserves, though, to avoid
+ * depletion of all memory. This prevents mm->mmap_sem livelock when an
+ * oom killed thread 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(p)
+ if (p->mm == mm && !same_thread_group(p, victim) &&
+ !(p->flags & PF_KTHREAD)) {
+ if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
+ continue;
+
+ task_lock(p); /* Protect ->comm from prctl() */
+ pr_err("Kill process %d (%s) sharing same memory\n",
+ task_pid_nr(p), p->comm);
+ task_unlock(p);
+ do_send_sig_info(SIGKILL, SEND_SIG_FORCED, p, true);
+ }
+
+ set_tsk_thread_flag(victim, TIF_MEMDIE);
+ do_send_sig_info(SIGKILL, SEND_SIG_FORCED, victim, true);
}
+#undef K
/*
* Determines whether the kernel must panic because of the panic_on_oom sysctl.
}
#ifdef CONFIG_CGROUP_MEM_RES_CTLR
-void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask)
+void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
+ int order)
{
unsigned long limit;
unsigned int points = 0;
return;
}
- check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, 0, NULL);
+ check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL);
limit = mem_cgroup_get_limit(memcg) >> PAGE_SHIFT;
read_lock(&tasklist_lock);
- p = select_bad_process(&points, limit, memcg, NULL);
+ p = select_bad_process(&points, limit, memcg, NULL, false);
if (p && PTR_ERR(p) != -1UL)
- oom_kill_process(p, gfp_mask, 0, points, limit, memcg, NULL,
+ oom_kill_process(p, gfp_mask, order, points, limit, memcg, NULL,
"Memory cgroup out of memory");
read_unlock(&tasklist_lock);
}
* @gfp_mask: memory allocation flags
* @order: amount of memory being requested as a power of 2
* @nodemask: nodemask passed to page allocator
+ * @force_kill: true if a task must be killed, even if others are exiting
*
* If we run out of memory, we have the choice between either
* killing a random task (bad), letting the system crash (worse)
* don't have to be perfect here, we just have to be good.
*/
void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,
- int order, nodemask_t *nodemask)
+ int order, nodemask_t *nodemask, bool force_kill)
{
const nodemask_t *mpol_mask;
struct task_struct *p;
goto out;
}
- p = select_bad_process(&points, totalpages, NULL, mpol_mask);
+ p = select_bad_process(&points, totalpages, NULL, mpol_mask,
+ force_kill);
/* Found nothing?!?! Either we hang forever, or we panic. */
if (!p) {
dump_header(NULL, gfp_mask, order, NULL, mpol_mask);
void pagefault_out_of_memory(void)
{
if (try_set_system_oom()) {
- out_of_memory(NULL, 0, 0, NULL);
+ out_of_memory(NULL, 0, 0, NULL, false);
clear_system_oom();
}
if (!test_thread_flag(TIF_MEMDIE))