From: Qiang Huang <h.huangqiang@huawei.com>
Date: Tue, 12 Nov 2013 23:07:22 +0000 (-0800)
Subject: mm: add a helper function to check may oom condition
X-Git-Tag: firefly_0821_release~176^2~4993^2~233
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b9921ecdee66984b00c38c00a358ef3f611d2b50;p=firefly-linux-kernel-4.4.55.git

mm: add a helper function to check may oom condition

Use helper function to check if we need to deal with oom condition.

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/include/linux/oom.h b/include/linux/oom.h
index da60007075b5..4cd62677feb9 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -82,6 +82,11 @@ static inline void oom_killer_enable(void)
 	oom_killer_disabled = false;
 }
 
+static inline bool oom_gfp_allowed(gfp_t gfp_mask)
+{
+	return (gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY);
+}
+
 extern struct task_struct *find_lock_task_mm(struct task_struct *p);
 
 /* sysctls */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 13b9d0f221b8..3427de9897a5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2984,21 +2984,14 @@ static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
 	struct res_counter *fail_res;
 	struct mem_cgroup *_memcg;
 	int ret = 0;
-	bool may_oom;
 
 	ret = res_counter_charge(&memcg->kmem, size, &fail_res);
 	if (ret)
 		return ret;
 
-	/*
-	 * Conditions under which we can wait for the oom_killer. Those are
-	 * the same conditions tested by the core page allocator
-	 */
-	may_oom = (gfp & __GFP_FS) && !(gfp & __GFP_NORETRY);
-
 	_memcg = memcg;
 	ret = __mem_cgroup_try_charge(NULL, gfp, size >> PAGE_SHIFT,
-				      &_memcg, may_oom);
+				      &_memcg, oom_gfp_allowed(gfp));
 
 	if (ret == -EINTR)  {
 		/*
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3d1d75a6629f..e0412c026e0d 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2593,7 +2593,7 @@ rebalance:
 	 * running out of options and have to consider going OOM
 	 */
 	if (!did_some_progress) {
-		if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
+		if (oom_gfp_allowed(gfp_mask)) {
 			if (oom_killer_disabled)
 				goto nopage;
 			/* Coredumps can quickly deplete all memory reserves */