diff --git a/include/linux/oom.h b/include/linux/oom.h index 922dab164eb..da60007075b 100644 --- a/include/linux/oom.h +++ b/include/linux/oom.h @@ -29,8 +29,23 @@ enum oom_scan_t { OOM_SCAN_SELECT, /* always select this thread first */ }; -extern void compare_swap_oom_score_adj(short old_val, short new_val); -extern short test_set_oom_score_adj(short new_val); +/* Thread is the potential origin of an oom condition; kill first on oom */ +#define OOM_FLAG_ORIGIN ((__force oom_flags_t)0x1) + +static inline void set_current_oom_origin(void) +{ + current->signal->oom_flags |= OOM_FLAG_ORIGIN; +} + +static inline void clear_current_oom_origin(void) +{ + current->signal->oom_flags &= ~OOM_FLAG_ORIGIN; +} + +static inline bool oom_task_origin(const struct task_struct *p) +{ + return !!(p->signal->oom_flags & OOM_FLAG_ORIGIN); +} extern unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg, const nodemask_t *nodemask, diff --git a/include/linux/sched.h b/include/linux/sched.h index ed30456152d..3e387df065f 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -631,6 +631,7 @@ struct signal_struct { struct rw_semaphore group_rwsem; #endif + oom_flags_t oom_flags; short oom_score_adj; /* OOM kill score adjustment */ short oom_score_adj_min; /* OOM kill score adjustment min value. * Only settable by CAP_SYS_RESOURCE. */ diff --git a/include/linux/types.h b/include/linux/types.h index 1cc0e4b9a04..4d118ba1134 100644 --- a/include/linux/types.h +++ b/include/linux/types.h @@ -156,6 +156,7 @@ typedef u32 dma_addr_t; #endif typedef unsigned __bitwise__ gfp_t; typedef unsigned __bitwise__ fmode_t; +typedef unsigned __bitwise__ oom_flags_t; #ifdef CONFIG_PHYS_ADDR_T_64BIT typedef u64 phys_addr_t; diff --git a/mm/ksm.c b/mm/ksm.c index b4d5a9deb17..382d930a0bf 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -1919,12 +1919,9 @@ static ssize_t run_store(struct kobject *kobj, struct kobj_attribute *attr, if (ksm_run != flags) { ksm_run = flags; if (flags & KSM_RUN_UNMERGE) { - short oom_score_adj; - - oom_score_adj = test_set_oom_score_adj(OOM_SCORE_ADJ_MAX); + set_current_oom_origin(); err = unmerge_and_remove_all_rmap_items(); - compare_swap_oom_score_adj(OOM_SCORE_ADJ_MAX, - oom_score_adj); + clear_current_oom_origin(); if (err) { ksm_run = KSM_RUN_STOP; count = err; diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 37ab4c5ab6e..18f1ae2b45d 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -44,48 +44,6 @@ int sysctl_oom_kill_allocating_task; int sysctl_oom_dump_tasks = 1; static DEFINE_SPINLOCK(zone_scan_lock); -/* - * compare_swap_oom_score_adj() - compare and swap current's oom_score_adj - * @old_val: old oom_score_adj for compare - * @new_val: new oom_score_adj for swap - * - * Sets the oom_score_adj value for current to @new_val iff its present value is - * @old_val. Usually used to reinstate a previous value to prevent racing with - * userspacing tuning the value in the interim. - */ -void compare_swap_oom_score_adj(short old_val, short new_val) -{ - struct sighand_struct *sighand = current->sighand; - - spin_lock_irq(&sighand->siglock); - if (current->signal->oom_score_adj == old_val) - current->signal->oom_score_adj = new_val; - trace_oom_score_adj_update(current); - spin_unlock_irq(&sighand->siglock); -} - -/** - * test_set_oom_score_adj() - set current's oom_score_adj and return old value - * @new_val: new oom_score_adj value - * - * Sets the oom_score_adj value for current to @new_val with proper - * synchronization and returns the old value. Usually used to temporarily - * set a value, save the old value in the caller, and then reinstate it later. - */ -short test_set_oom_score_adj(short new_val) -{ - struct sighand_struct *sighand = current->sighand; - int old_val; - - spin_lock_irq(&sighand->siglock); - old_val = current->signal->oom_score_adj; - current->signal->oom_score_adj = new_val; - trace_oom_score_adj_update(current); - spin_unlock_irq(&sighand->siglock); - - return old_val; -} - #ifdef CONFIG_NUMA /** * has_intersects_mems_allowed() - check task eligiblity for kill @@ -310,6 +268,13 @@ enum oom_scan_t oom_scan_process_thread(struct task_struct *task, if (!task->mm) return OOM_SCAN_CONTINUE; + /* + * If task is allocating a lot of memory and has been marked to be + * killed first if it triggers an oom, then select it. + */ + if (oom_task_origin(task)) + return OOM_SCAN_SELECT; + if (task->flags & PF_EXITING && !force_kill) { /* * If this task is not being ptraced on exit, then wait for it diff --git a/mm/swapfile.c b/mm/swapfile.c index bb6f6a04e92..e97a0e5aea9 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1498,7 +1498,6 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile) struct address_space *mapping; struct inode *inode; struct filename *pathname; - short oom_score_adj; int i, type, prev; int err; @@ -1557,9 +1556,9 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile) p->flags &= ~SWP_WRITEOK; spin_unlock(&swap_lock); - oom_score_adj = test_set_oom_score_adj(OOM_SCORE_ADJ_MAX); + set_current_oom_origin(); err = try_to_unuse(type, false, 0); /* force all pages to be unused */ - compare_swap_oom_score_adj(OOM_SCORE_ADJ_MAX, oom_score_adj); + clear_current_oom_origin(); if (err) { /* re-insert swap space back into swap_list */