| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame^] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | #ifndef __INCLUDE_LINUX_OOM_H |
| 3 | #define __INCLUDE_LINUX_OOM_H |
| 4 | |
| 5 | |
| 6 | #include <linux/sched/signal.h> |
| 7 | #include <linux/types.h> |
| 8 | #include <linux/nodemask.h> |
| 9 | #include <uapi/linux/oom.h> |
| 10 | #include <linux/sched/coredump.h> /* MMF_* */ |
| 11 | #include <linux/mm.h> /* VM_FAULT* */ |
| 12 | |
| 13 | struct zonelist; |
| 14 | struct notifier_block; |
| 15 | struct mem_cgroup; |
| 16 | struct task_struct; |
| 17 | |
| 18 | /* |
| 19 | * Details of the page allocation that triggered the oom killer that are used to |
| 20 | * determine what should be killed. |
| 21 | */ |
| 22 | struct oom_control { |
| 23 | /* Used to determine cpuset */ |
| 24 | struct zonelist *zonelist; |
| 25 | |
| 26 | /* Used to determine mempolicy */ |
| 27 | nodemask_t *nodemask; |
| 28 | |
| 29 | /* Memory cgroup in which oom is invoked, or NULL for global oom */ |
| 30 | struct mem_cgroup *memcg; |
| 31 | |
| 32 | /* Used to determine cpuset and node locality requirement */ |
| 33 | const gfp_t gfp_mask; |
| 34 | |
| 35 | /* |
| 36 | * order == -1 means the oom kill is required by sysrq, otherwise only |
| 37 | * for display purposes. |
| 38 | */ |
| 39 | const int order; |
| 40 | |
| 41 | /* Used by oom implementation, do not set */ |
| 42 | unsigned long totalpages; |
| 43 | struct task_struct *chosen; |
| 44 | unsigned long chosen_points; |
| 45 | }; |
| 46 | |
| 47 | extern struct mutex oom_lock; |
| 48 | |
| 49 | static inline void set_current_oom_origin(void) |
| 50 | { |
| 51 | current->signal->oom_flag_origin = true; |
| 52 | } |
| 53 | |
| 54 | static inline void clear_current_oom_origin(void) |
| 55 | { |
| 56 | current->signal->oom_flag_origin = false; |
| 57 | } |
| 58 | |
| 59 | static inline bool oom_task_origin(const struct task_struct *p) |
| 60 | { |
| 61 | return p->signal->oom_flag_origin; |
| 62 | } |
| 63 | |
| 64 | static inline bool tsk_is_oom_victim(struct task_struct * tsk) |
| 65 | { |
| 66 | return tsk->signal->oom_mm; |
| 67 | } |
| 68 | |
| 69 | /* |
| 70 | * Use this helper if tsk->mm != mm and the victim mm needs a special |
| 71 | * handling. This is guaranteed to stay true after once set. |
| 72 | */ |
| 73 | static inline bool mm_is_oom_victim(struct mm_struct *mm) |
| 74 | { |
| 75 | return test_bit(MMF_OOM_VICTIM, &mm->flags); |
| 76 | } |
| 77 | |
| 78 | /* |
| 79 | * Checks whether a page fault on the given mm is still reliable. |
| 80 | * This is no longer true if the oom reaper started to reap the |
| 81 | * address space which is reflected by MMF_UNSTABLE flag set in |
| 82 | * the mm. At that moment any !shared mapping would lose the content |
| 83 | * and could cause a memory corruption (zero pages instead of the |
| 84 | * original content). |
| 85 | * |
| 86 | * User should call this before establishing a page table entry for |
| 87 | * a !shared mapping and under the proper page table lock. |
| 88 | * |
| 89 | * Return 0 when the PF is safe VM_FAULT_SIGBUS otherwise. |
| 90 | */ |
| 91 | static inline vm_fault_t check_stable_address_space(struct mm_struct *mm) |
| 92 | { |
| 93 | if (unlikely(test_bit(MMF_UNSTABLE, &mm->flags))) |
| 94 | return VM_FAULT_SIGBUS; |
| 95 | return 0; |
| 96 | } |
| 97 | |
| 98 | bool __oom_reap_task_mm(struct mm_struct *mm); |
| 99 | |
| 100 | extern unsigned long oom_badness(struct task_struct *p, |
| 101 | struct mem_cgroup *memcg, const nodemask_t *nodemask, |
| 102 | unsigned long totalpages); |
| 103 | |
| 104 | extern bool out_of_memory(struct oom_control *oc); |
| 105 | |
| 106 | extern void exit_oom_victim(void); |
| 107 | |
| 108 | extern int register_oom_notifier(struct notifier_block *nb); |
| 109 | extern int unregister_oom_notifier(struct notifier_block *nb); |
| 110 | |
| 111 | extern bool oom_killer_disable(signed long timeout); |
| 112 | extern void oom_killer_enable(void); |
| 113 | |
| 114 | extern struct task_struct *find_lock_task_mm(struct task_struct *p); |
| 115 | |
| 116 | /* sysctls */ |
| 117 | extern int sysctl_oom_dump_tasks; |
| 118 | extern int sysctl_oom_kill_allocating_task; |
| 119 | extern int sysctl_panic_on_oom; |
| 120 | #endif /* _INCLUDE_LINUX_OOM_H */ |