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-rw-r--r--fs/proc/base.c3
-rw-r--r--include/linux/oom.h1
-rw-r--r--include/linux/sched/coredump.h1
-rw-r--r--kernel/fork.c21
-rw-r--r--mm/oom_kill.c2
5 files changed, 26 insertions, 2 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 617db4e0faa0..aa69c35d904c 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1055,7 +1055,6 @@ static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
{
- static DEFINE_MUTEX(oom_adj_mutex);
struct mm_struct *mm = NULL;
struct task_struct *task;
int err = 0;
@@ -1095,7 +1094,7 @@ static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
struct task_struct *p = find_lock_task_mm(task);
if (p) {
- if (atomic_read(&p->mm->mm_users) > 1) {
+ if (test_bit(MMF_MULTIPROCESS, &p->mm->flags)) {
mm = p->mm;
mmgrab(mm);
}
diff --git a/include/linux/oom.h b/include/linux/oom.h
index f022f581ac29..2db9a1432511 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -55,6 +55,7 @@ struct oom_control {
};
extern struct mutex oom_lock;
+extern struct mutex oom_adj_mutex;
static inline void set_current_oom_origin(void)
{
diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredump.h
index ecdc6542070f..dfd82eab2902 100644
--- a/include/linux/sched/coredump.h
+++ b/include/linux/sched/coredump.h
@@ -72,6 +72,7 @@ static inline int get_dumpable(struct mm_struct *mm)
#define MMF_DISABLE_THP 24 /* disable THP for all VMAs */
#define MMF_OOM_VICTIM 25 /* mm is the oom victim */
#define MMF_OOM_REAP_QUEUED 26 /* mm was queued for oom_reaper */
+#define MMF_MULTIPROCESS 27 /* mm is shared between processes */
#define MMF_DISABLE_THP_MASK (1 << MMF_DISABLE_THP)
#define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\
diff --git a/kernel/fork.c b/kernel/fork.c
index ede26e5a6097..50c90d368117 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1812,6 +1812,25 @@ static __always_inline void delayed_free_task(struct task_struct *tsk)
free_task(tsk);
}
+static void copy_oom_score_adj(u64 clone_flags, struct task_struct *tsk)
+{
+ /* Skip if kernel thread */
+ if (!tsk->mm)
+ return;
+
+ /* Skip if spawning a thread or using vfork */
+ if ((clone_flags & (CLONE_VM | CLONE_THREAD | CLONE_VFORK)) != CLONE_VM)
+ return;
+
+ /* We need to synchronize with __set_oom_adj */
+ mutex_lock(&oom_adj_mutex);
+ set_bit(MMF_MULTIPROCESS, &tsk->mm->flags);
+ /* Update the values in case they were changed after copy_signal */
+ tsk->signal->oom_score_adj = current->signal->oom_score_adj;
+ tsk->signal->oom_score_adj_min = current->signal->oom_score_adj_min;
+ mutex_unlock(&oom_adj_mutex);
+}
+
/*
* This creates a new process as a copy of the old one,
* but does not actually start it yet.
@@ -2288,6 +2307,8 @@ static __latent_entropy struct task_struct *copy_process(
trace_task_newtask(p, clone_flags);
uprobe_copy_process(p, clone_flags);
+ copy_oom_score_adj(clone_flags, p);
+
return p;
bad_fork_cancel_cgroup:
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index e90f25d6385d..8b84661a6410 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -64,6 +64,8 @@ int sysctl_oom_dump_tasks = 1;
* and mark_oom_victim
*/
DEFINE_MUTEX(oom_lock);
+/* Serializes oom_score_adj and oom_score_adj_min updates */
+DEFINE_MUTEX(oom_adj_mutex);
static inline bool is_memcg_oom(struct oom_control *oc)
{