diff options
| -rw-r--r-- | fs/proc/base.c | 46 | ||||
| -rw-r--r-- | include/linux/mm.h | 2 | ||||
| -rw-r--r-- | mm/oom_kill.c | 2 |
3 files changed, 49 insertions, 1 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 13a345952cc7..31370da2ee7c 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1040,6 +1040,7 @@ 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; @@ -1069,10 +1070,55 @@ static int __set_oom_adj(struct file *file, int oom_adj, bool legacy) } } + /* + * Make sure we will check other processes sharing the mm if this is + * not vfrok which wants its own oom_score_adj. + * pin the mm so it doesn't go away and get reused after task_unlock + */ + if (!task->vfork_done) { + struct task_struct *p = find_lock_task_mm(task); + + if (p) { + if (atomic_read(&p->mm->mm_users) > 1) { + mm = p->mm; + atomic_inc(&mm->mm_count); + } + task_unlock(p); + } + } + task->signal->oom_score_adj = oom_adj; if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) task->signal->oom_score_adj_min = (short)oom_adj; trace_oom_score_adj_update(task); + + if (mm) { + struct task_struct *p; + + rcu_read_lock(); + for_each_process(p) { + if (same_thread_group(task, p)) + continue; + + /* do not touch kernel threads or the global init */ + if (p->flags & PF_KTHREAD || is_global_init(p)) + continue; + + task_lock(p); + if (!p->vfork_done && process_shares_mm(p, mm)) { + pr_info("updating oom_score_adj for %d (%s) from %d to %d because it shares mm with %d (%s). Report if this is unexpected.\n", + task_pid_nr(p), p->comm, + p->signal->oom_score_adj, oom_adj, + task_pid_nr(task), task->comm); + p->signal->oom_score_adj = oom_adj; + if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE)) + p->signal->oom_score_adj_min = (short)oom_adj; + } + task_unlock(p); + } + rcu_read_unlock(); + mmdrop(mm); + } err_unlock: mutex_unlock(&oom_adj_mutex); put_task_struct(task); diff --git a/include/linux/mm.h b/include/linux/mm.h index 192c1bbe5fcd..c606fe4f9a7f 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2284,6 +2284,8 @@ static inline int in_gate_area(struct mm_struct *mm, unsigned long addr) } #endif /* __HAVE_ARCH_GATE_AREA */ +extern bool process_shares_mm(struct task_struct *p, struct mm_struct *mm); + #ifdef CONFIG_SYSCTL extern int sysctl_drop_caches; int drop_caches_sysctl_handler(struct ctl_table *, int, diff --git a/mm/oom_kill.c b/mm/oom_kill.c index d4a929d79470..d8220c5603a5 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -415,7 +415,7 @@ bool oom_killer_disabled __read_mostly; * task's threads: if one of those is using this mm then this task was also * using it. */ -static bool process_shares_mm(struct task_struct *p, struct mm_struct *mm) +bool process_shares_mm(struct task_struct *p, struct mm_struct *mm) { struct task_struct *t; |