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 enum oom_constraint { 19 CONSTRAINT_NONE, 20 CONSTRAINT_CPUSET, 21 CONSTRAINT_MEMORY_POLICY, 22 CONSTRAINT_MEMCG, 23 }; 24 25 /* 26 * Details of the page allocation that triggered the oom killer that are used to 27 * determine what should be killed. 28 */ 29 struct oom_control { 30 /* Used to determine cpuset */ 31 struct zonelist *zonelist; 32 33 /* Used to determine mempolicy */ 34 nodemask_t *nodemask; 35 36 /* Memory cgroup in which oom is invoked, or NULL for global oom */ 37 struct mem_cgroup *memcg; 38 39 /* Used to determine cpuset and node locality requirement */ 40 const gfp_t gfp_mask; 41 42 /* 43 * order == -1 means the oom kill is required by sysrq, otherwise only 44 * for display purposes. 45 */ 46 const int order; 47 48 /* Used by oom implementation, do not set */ 49 unsigned long totalpages; 50 struct task_struct *chosen; 51 long chosen_points; 52 53 /* Used to print the constraint info. */ 54 enum oom_constraint constraint; 55 }; 56 57 extern struct mutex oom_lock; 58 extern struct mutex oom_adj_mutex; 59 60 static inline void set_current_oom_origin(void) 61 { 62 current->signal->oom_flag_origin = true; 63 } 64 65 static inline void clear_current_oom_origin(void) 66 { 67 current->signal->oom_flag_origin = false; 68 } 69 70 static inline bool oom_task_origin(const struct task_struct *p) 71 { 72 return p->signal->oom_flag_origin; 73 } 74 75 static inline bool tsk_is_oom_victim(struct task_struct * tsk) 76 { 77 return tsk->signal->oom_mm; 78 } 79 80 /* 81 * Checks whether a page fault on the given mm is still reliable. 82 * This is no longer true if the oom reaper started to reap the 83 * address space which is reflected by MMF_UNSTABLE flag set in 84 * the mm. At that moment any !shared mapping would lose the content 85 * and could cause a memory corruption (zero pages instead of the 86 * original content). 87 * 88 * User should call this before establishing a page table entry for 89 * a !shared mapping and under the proper page table lock. 90 * 91 * Return 0 when the PF is safe VM_FAULT_SIGBUS otherwise. 92 */ 93 static inline vm_fault_t check_stable_address_space(struct mm_struct *mm) 94 { 95 if (unlikely(test_bit(MMF_UNSTABLE, &mm->flags))) 96 return VM_FAULT_SIGBUS; 97 return 0; 98 } 99 100 long oom_badness(struct task_struct *p, 101 unsigned long totalpages); 102 103 extern bool out_of_memory(struct oom_control *oc); 104 105 extern void exit_oom_victim(void); 106 107 extern int register_oom_notifier(struct notifier_block *nb); 108 extern int unregister_oom_notifier(struct notifier_block *nb); 109 110 extern bool oom_killer_disable(signed long timeout); 111 extern void oom_killer_enable(void); 112 113 extern struct task_struct *find_lock_task_mm(struct task_struct *p); 114 115 #endif /* _INCLUDE_LINUX_OOM_H */ 116