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 int 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 void __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 */ 121