From: Sha Zhengju <handai.szj@xxxxxxxxxx>
If memcg oom happening, don't scan all system tasks to dump memory state of
eligible tasks, instead we iterates only over the process attached to the oom
memcg and avoid the rcu lock.
Signed-off-by: Sha Zhengju <handai.szj@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/memcontrol.h | 7 +++++
include/linux/oom.h | 2 +
mm/memcontrol.c | 14 +++++++++++
mm/oom_kill.c | 55 ++++++++++++++++++++++++++-----------------
4 files changed, 56 insertions(+), 22 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index c91e3c1..4322ca8 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -122,6 +122,8 @@ unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list);
void mem_cgroup_update_lru_size(struct lruvec *, enum lru_list, int);
extern void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
struct task_struct *p);
+extern void dump_tasks_memcg(const struct mem_cgroup *memcg,
+ const nodemask_t *nodemask);
extern void mem_cgroup_replace_page_cache(struct page *oldpage,
struct page *newpage);
@@ -337,6 +339,11 @@ mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
{
}
+static inline void
+dump_tasks_memcg(const struct mem_cgroup *memcg, const nodemask_t *nodemask)
+{
+}
+
static inline void mem_cgroup_begin_update_page_stat(struct page *page,
bool *locked, unsigned long *flags)
{
diff --git a/include/linux/oom.h b/include/linux/oom.h
index 20b5c46..9ba3344 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -57,6 +57,8 @@ extern enum oom_scan_t oom_scan_process_thread(struct task_struct *task,
unsigned long totalpages, const nodemask_t *nodemask,
bool force_kill);
+extern inline void dump_per_task(struct task_struct *p,
+ const nodemask_t *nodemask);
extern void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,
int order, nodemask_t *mask, bool force_kill);
extern int register_oom_notifier(struct notifier_block *nb);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 2df5e72..fe648f8 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1665,6 +1665,20 @@ static u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
return min(limit, memsw);
}
+void dump_tasks_memcg(const struct mem_cgroup *memcg, const nodemask_t *nodemask)
+{
+ struct cgroup_iter it;
+ struct task_struct *task;
+ struct cgroup *cgroup = memcg->css.cgroup;
+
+ cgroup_iter_start(cgroup, &it);
+ while ((task = cgroup_iter_next(cgroup, &it))) {
+ dump_per_task(task, nodemask);
+ }
+
+ cgroup_iter_end(cgroup, &it);
+}
+
static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
int order)
{
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 4b8a6dd..aaf6237 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -367,6 +367,32 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
return chosen;
}
+inline void dump_per_task(struct task_struct *p, const nodemask_t *nodemask)
+{
+ struct task_struct *task;
+
+ if (oom_unkillable_task(p, NULL, nodemask))
+ return;
+
+ task = find_lock_task_mm(p);
+ if (!task) {
+ /*
+ * This is a kthread or all of p's threads have already
+ * detached their mm's. There's no need to report
+ * them; they can't be oom killed anyway.
+ */
+ return;
+ }
+
+ pr_info("[%5d] %5d %5d %8lu %8lu %7lu %8lu %5d %s\n",
+ task->pid, from_kuid(&init_user_ns, task_uid(task)),
+ task->tgid, task->mm->total_vm, get_mm_rss(task->mm),
+ task->mm->nr_ptes,
+ get_mm_counter(task->mm, MM_SWAPENTS),
+ task->signal->oom_score_adj, task->comm);
+ task_unlock(task);
+}
+
/**
* dump_tasks - dump current memory state of all system tasks
* @memcg: current's memory controller, if constrained
@@ -381,32 +407,17 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
static void dump_tasks(const struct mem_cgroup *memcg, const nodemask_t *nodemask)
{
struct task_struct *p;
- struct task_struct *task;
pr_info("[ pid ] uid tgid total_vm rss nr_ptes swapents oom_score_adj name\n");
- rcu_read_lock();
- for_each_process(p) {
- if (oom_unkillable_task(p, memcg, nodemask))
- continue;
-
- task = find_lock_task_mm(p);
- if (!task) {
- /*
- * This is a kthread or all of p's threads have already
- * detached their mm's. There's no need to report
- * them; they can't be oom killed anyway.
- */
- continue;
- }
- pr_info("[%5d] %5d %5d %8lu %8lu %7lu %8lu %5d %s\n",
- task->pid, from_kuid(&init_user_ns, task_uid(task)),
- task->tgid, task->mm->total_vm, get_mm_rss(task->mm),
- task->mm->nr_ptes,
- get_mm_counter(task->mm, MM_SWAPENTS),
- task->signal->oom_score_adj, task->comm);
- task_unlock(task);
+ if (memcg) {
+ dump_tasks_memcg(memcg, nodemask);
+ return;
}
+
+ rcu_read_lock();
+ for_each_process(p)
+ dump_per_task(p, nodemask);
rcu_read_unlock();
}
--
1.7.6.1
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