path: root/mm/oom_kill.c
diff options
authorShakeel Butt <>2019-07-11 21:00:26 -0700
committerLinus Torvalds <>2019-07-12 11:05:47 -0700
commit6ba749ee78ef42ffdf4b95c042fc574a37d229d9 (patch)
treecfe8087747269d44a79dbeecb6be94c82d9af034 /mm/oom_kill.c
parent5eee7e1cdb97123bb55ac14ccd3af8b6edc31537 (diff)
mm, oom: remove redundant task_in_mem_cgroup() check
oom_unkillable_task() can be called from three different contexts i.e. global OOM, memcg OOM and oom_score procfs interface. At the moment oom_unkillable_task() does a task_in_mem_cgroup() check on the given process. Since there is no reason to perform task_in_mem_cgroup() check for global OOM and oom_score procfs interface, those contexts provide NULL memcg and skips the task_in_mem_cgroup() check. However for memcg OOM context, the oom_unkillable_task() is always called from mem_cgroup_scan_tasks() and thus task_in_mem_cgroup() check becomes redundant and effectively dead code. So, just remove the task_in_mem_cgroup() check altogether. Link: Signed-off-by: Shakeel Butt <> Signed-off-by: Tetsuo Handa <> Acked-by: Roman Gushchin <> Acked-by: Michal Hocko <> Cc: David Rientjes <> Cc: Johannes Weiner <> Cc: KOSAKI Motohiro <> Cc: Nick Piggin <> Cc: Paul Jackson <> Cc: Vladimir Davydov <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'mm/oom_kill.c')
1 files changed, 7 insertions, 12 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 59326614508a..b353f468a36a 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -153,17 +153,13 @@ static inline bool is_memcg_oom(struct oom_control *oc)
/* return true if the task is not adequate as candidate victim task. */
static bool oom_unkillable_task(struct task_struct *p,
- struct mem_cgroup *memcg, const nodemask_t *nodemask)
+ const nodemask_t *nodemask)
if (is_global_init(p))
return true;
if (p->flags & PF_KTHREAD)
return true;
- /* When mem_cgroup_out_of_memory() and p is not member of the group */
- if (memcg && !task_in_mem_cgroup(p, memcg))
- return true;
/* p may not have freeable memory in nodemask */
if (!has_intersects_mems_allowed(p, nodemask))
return true;
@@ -194,20 +190,19 @@ static bool is_dump_unreclaim_slabs(void)
* oom_badness - heuristic function to determine which candidate task to kill
* @p: task struct of which task we should calculate
* @totalpages: total present RAM allowed for page allocation
- * @memcg: task's memory controller, if constrained
* @nodemask: nodemask passed to page allocator for mempolicy ooms
* The heuristic for determining which task to kill is made to be as simple and
* predictable as possible. The goal is to return the highest value for the
* task consuming the most memory to avoid subsequent oom failures.
-unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg,
+unsigned long oom_badness(struct task_struct *p,
const nodemask_t *nodemask, unsigned long totalpages)
long points;
long adj;
- if (oom_unkillable_task(p, memcg, nodemask))
+ if (oom_unkillable_task(p, nodemask))
return 0;
p = find_lock_task_mm(p);
@@ -318,7 +313,7 @@ static int oom_evaluate_task(struct task_struct *task, void *arg)
struct oom_control *oc = arg;
unsigned long points;
- if (oom_unkillable_task(task, NULL, oc->nodemask))
+ if (oom_unkillable_task(task, oc->nodemask))
goto next;
@@ -342,7 +337,7 @@ static int oom_evaluate_task(struct task_struct *task, void *arg)
goto select;
- points = oom_badness(task, NULL, oc->nodemask, oc->totalpages);
+ points = oom_badness(task, oc->nodemask, oc->totalpages);
if (!points || points < oc->chosen_points)
goto next;
@@ -387,7 +382,7 @@ static int dump_task(struct task_struct *p, void *arg)
struct oom_control *oc = arg;
struct task_struct *task;
- if (oom_unkillable_task(p, NULL, oc->nodemask))
+ if (oom_unkillable_task(p, oc->nodemask))
return 0;
task = find_lock_task_mm(p);
@@ -1084,7 +1079,7 @@ bool out_of_memory(struct oom_control *oc)
if (!is_memcg_oom(oc) && sysctl_oom_kill_allocating_task &&
- current->mm && !oom_unkillable_task(current, NULL, oc->nodemask) &&
+ current->mm && !oom_unkillable_task(current, oc->nodemask) &&
current->signal->oom_score_adj != OOM_SCORE_ADJ_MIN) {
oc->chosen = current;