diff options
| -rw-r--r-- | mm/oom_kill.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 4395f371bc7c..7dcca55ede7c 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -404,16 +404,40 @@ static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order, #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); |