X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=mm%2Foom_kill.c;h=a66b2703e917ea4cca231f22cf99188060cabeef;hb=021d5b54c47408099822a47f49d35dd4dc63b8b3;hp=29f855551efef89d6c251075828bc0cd79da1842;hpb=9035a8961b504d0997369509ab8c6b1f0a4ee33d;p=mirror_ubuntu-bionic-kernel.git

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 29f855551efe..a66b2703e917 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -474,7 +474,6 @@ bool process_shares_mm(struct task_struct *p, struct mm_struct *mm)
 	return false;
 }
 
-
 #ifdef CONFIG_MMU
 /*
  * OOM Reaper kernel thread which tries to reap the memory used by the OOM
@@ -485,16 +484,51 @@ static DECLARE_WAIT_QUEUE_HEAD(oom_reaper_wait);
 static struct task_struct *oom_reaper_list;
 static DEFINE_SPINLOCK(oom_reaper_lock);
 
-static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
+void __oom_reap_task_mm(struct mm_struct *mm)
 {
-	struct mmu_gather tlb;
 	struct vm_area_struct *vma;
+
+	/*
+	 * Tell all users of get_user/copy_from_user etc... that the content
+	 * is no longer stable. No barriers really needed because unmapping
+	 * should imply barriers already and the reader would hit a page fault
+	 * if it stumbled over a reaped memory.
+	 */
+	set_bit(MMF_UNSTABLE, &mm->flags);
+
+	for (vma = mm->mmap ; vma; vma = vma->vm_next) {
+		if (!can_madv_dontneed_vma(vma))
+			continue;
+
+		/*
+		 * Only anonymous pages have a good chance to be dropped
+		 * without additional steps which we cannot afford as we
+		 * are OOM already.
+		 *
+		 * We do not even care about fs backed pages because all
+		 * which are reclaimable have already been reclaimed and
+		 * we do not want to block exit_mmap by keeping mm ref
+		 * count elevated without a good reason.
+		 */
+		if (vma_is_anonymous(vma) || !(vma->vm_flags & VM_SHARED)) {
+			struct mmu_gather tlb;
+
+			tlb_gather_mmu(&tlb, mm, vma->vm_start, vma->vm_end);
+			unmap_page_range(&tlb, vma, vma->vm_start, vma->vm_end,
+					 NULL);
+			tlb_finish_mmu(&tlb, vma->vm_start, vma->vm_end);
+		}
+	}
+}
+
+static bool oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
+{
 	bool ret = true;
 
 	/*
 	 * We have to make sure to not race with the victim exit path
 	 * and cause premature new oom victim selection:
-	 * __oom_reap_task_mm		exit_mm
+	 * oom_reap_task_mm		exit_mm
 	 *   mmget_not_zero
 	 *				  mmput
 	 *				    atomic_dec_and_test
@@ -542,35 +576,8 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
 
 	trace_start_task_reaping(tsk->pid);
 
-	/*
-	 * Tell all users of get_user/copy_from_user etc... that the content
-	 * is no longer stable. No barriers really needed because unmapping
-	 * should imply barriers already and the reader would hit a page fault
-	 * if it stumbled over a reaped memory.
-	 */
-	set_bit(MMF_UNSTABLE, &mm->flags);
-
-	for (vma = mm->mmap ; vma; vma = vma->vm_next) {
-		if (!can_madv_dontneed_vma(vma))
-			continue;
+	__oom_reap_task_mm(mm);
 
-		/*
-		 * Only anonymous pages have a good chance to be dropped
-		 * without additional steps which we cannot afford as we
-		 * are OOM already.
-		 *
-		 * We do not even care about fs backed pages because all
-		 * which are reclaimable have already been reclaimed and
-		 * we do not want to block exit_mmap by keeping mm ref
-		 * count elevated without a good reason.
-		 */
-		if (vma_is_anonymous(vma) || !(vma->vm_flags & VM_SHARED)) {
-			tlb_gather_mmu(&tlb, mm, vma->vm_start, vma->vm_end);
-			unmap_page_range(&tlb, vma, vma->vm_start, vma->vm_end,
-					 NULL);
-			tlb_finish_mmu(&tlb, vma->vm_start, vma->vm_end);
-		}
-	}
 	pr_info("oom_reaper: reaped process %d (%s), now anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n",
 			task_pid_nr(tsk), tsk->comm,
 			K(get_mm_counter(mm, MM_ANONPAGES)),
@@ -591,13 +598,12 @@ static void oom_reap_task(struct task_struct *tsk)
 	struct mm_struct *mm = tsk->signal->oom_mm;
 
 	/* Retry the down_read_trylock(mmap_sem) a few times */
-	while (attempts++ < MAX_OOM_REAP_RETRIES && !__oom_reap_task_mm(tsk, mm))
+	while (attempts++ < MAX_OOM_REAP_RETRIES && !oom_reap_task_mm(tsk, mm))
 		schedule_timeout_idle(HZ/10);
 
 	if (attempts <= MAX_OOM_REAP_RETRIES)
 		goto done;
 
-
 	pr_info("oom_reaper: unable to reap pid:%d (%s)\n",
 		task_pid_nr(tsk), tsk->comm);
 	debug_show_all_locks();