[PATCH v2] mm, memcg: add a helper function to check may oom condition

Qiang Huang
2013-09-10T01:25:15Z

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

v2:
Change the function name to oom_gfp_allowed() as suggested by
David Rientjes.

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
---
include/linux/oom.h | 5 +++++
mm/memcontrol.c | 9 +--------
mm/page_alloc.c | 2 +-
3 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/include/linux/oom.h b/include/linux/oom.h
index da60007..4cd6267 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 b73988a..392e668 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2910,21 +2910,14 @@ 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 b7c612d..079ee3d 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2589,7 +2589,7 @@ 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 */
--
1.8.3

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