/* * linux/mm/oom_kill.c * * Copyright (C) 1998,2000 Rik van Riel * Thanks go out to Claus Fischer for some serious inspiration and * for goading me into coding this file... * Copyright (C) 2010 Google, Inc. * Rewritten by David Rientjes * * The routines in this file are used to kill a process when * we're seriously out of memory. This gets called from __alloc_pages() * in mm/page_alloc.c when we really run out of memory. * * Since we won't call these routines often (on a well-configured * machine) this file will double as a 'coding guide' and a signpost * for newbie kernel hackers. It features several pointers to major * kernel subsystems and hints as to where to find out what things do. */ #include <linux/oom.h>#include <linux/mm.h>#include <linux/err.h>#include <linux/gfp.h>#include <linux/sched.h>#include <linux/swap.h>#include <linux/timex.h>#include <linux/jiffies.h>#include <linux/cpuset.h>#include <linux/export.h>#include <linux/notifier.h>#include <linux/memcontrol.h>#include <linux/mempolicy.h>#include <linux/security.h>#include <linux/ptrace.h>#include <linux/freezer.h>#include <linux/ftrace.h>#include <linux/ratelimit.h> #define CREATE_TRACE_POINTS#include <trace/events/oom.h> int sysctl_panic_on_oom;int sysctl_oom_kill_allocating_task;int sysctl_oom_dump_tasks = 1;static DEFINE_SPINLOCK(zone_scan_lock); #ifdef CONFIG_NUMA/** * has_intersects_mems_allowed() - check task eligiblity for kill * @tsk: task struct of which task to consider * @mask: nodemask passed to page allocator for mempolicy ooms * * Task eligibility is determined by whether or not a candidate task, @tsk, * shares the same mempolicy nodes as current if it is bound by such a policy * and whether or not it has the same set of allowed cpuset nodes. */static bool has_intersects_mems_allowed(struct task_struct *tsk, const nodemask_t *mask){ struct task_struct *start = tsk; do { if (mask) { /* * If this is a mempolicy constrained oom, tsk's * cpuset is irrelevant. Only return true if its * mempolicy intersects current, otherwise it may be * needlessly killed. */ if (mempolicy_nodemask_intersects(tsk, mask)) return true; } else { /* * This is not a mempolicy constrained oom, so only * check the mems of tsk's cpuset. */ if (cpuset_mems_allowed_intersects(current, tsk)) return true; } } while_each_thread(start, tsk); return false;}#elsestatic bool has_intersects_mems_allowed(struct task_struct *tsk, const nodemask_t *mask){ return true;}#endif /* CONFIG_NUMA */ /* * The process p may have detached its own ->mm while exiting or through * use_mm(), but one or more of its subthreads may still have a valid * pointer. Return p, or any of its subthreads with a valid ->mm, with * task_lock() held. */struct task_struct *find_lock_task_mm(struct task_struct *p){ struct task_struct *t = p; do { task_lock(t); if (likely(t->mm)) return t; task_unlock(t); } while_each_thread(p, t); return NULL;} /* return true if the task is not adequate as candidate victim task. */static bool oom_unkillable_task(struct task_struct *p, const struct mem_cgroup *memcg, const nodemask_t *nodemask){ if (is_global_init(p)) return true; if (p->flags & PF_KTHREAD) return true; /* When mem_cgroup_out_of_memory() and p is not member of the group */ if (memcg && !task_in_mem_cgroup(p, memcg)) return true; /* p may not have freeable memory in nodemask */ if (!has_intersects_mems_allowed(p, nodemask)) return true; return false;} /** * oom_badness - heuristic function to determine which candidate task to kill * @p: task struct of which task we should calculate * @totalpages: total present RAM allowed for page allocation * * The heuristic for determining which task to kill is made to be as simple and * predictable as possible. The goal is to return the highest value for the * task consuming the most memory to avoid subsequent oom failures. */unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg, const nodemask_t *nodemask, unsigned long totalpages){ long points; long adj; if (oom_unkillable_task(p, memcg, nodemask)) return 0; p = find_lock_task_mm(p); if (!p) return 0; adj = (long)p->signal->oom_score_adj; if (adj == OOM_SCORE_ADJ_MIN) { task_unlock(p); return 0; } /* * The baseline for the badness score is the proportion of RAM that each * task's rss, pagetable and swap space use. */ points = get_mm_rss(p->mm) + atomic_long_read(&p->mm->nr_ptes) + get_mm_counter(p->mm, MM_SWAPENTS); task_unlock(p); /* * Root processes get 3% bonus, just like the __vm_enough_memory() * implementation used by LSMs. */ if (has_capability_noaudit(p, CAP_SYS_ADMIN)) adj -= 30; /* Normalize to oom_score_adj units */ adj *= totalpages / 1000; points += adj; /* * Never return 0 for an eligible task regardless of the root bonus and * oom_score_adj (oom_score_adj can't be OOM_SCORE_ADJ_MIN here). */ return points > 0 ? points : 1;} /* * Determine the type of allocation constraint. */#ifdef CONFIG_NUMAstatic enum oom_constraint constrained_alloc(struct zonelist *zonelist, gfp_t gfp_mask, nodemask_t *nodemask, unsigned long *totalpages){ struct zone *zone; struct zoneref *z; enum zone_type high_zoneidx = gfp_zone(gfp_mask); bool cpuset_limited = false; int nid; /* Default to all available memory */ *totalpages = totalram_pages + total_swap_pages; if (!zonelist) return CONSTRAINT_NONE; /* * Reach here only when __GFP_NOFAIL is used. So, we should avoid * to kill current.We have to random task kill in this case. * Hopefully, CONSTRAINT_THISNODE...but no way to handle it, now. */ if (gfp_mask & __GFP_THISNODE) return CONSTRAINT_NONE; /* * This is not a __GFP_THISNODE allocation, so a truncated nodemask in * the page allocator means a mempolicy is in effect. Cpuset policy * is enforced in get_page_from_freelist(). */ if (nodemask && !nodes_subset(node_states[N_MEMORY], *nodemask)) { *totalpages = total_swap_pages; for_each_node_mask(nid, *nodemask) *totalpages += node_spanned_pages(nid); return CONSTRAINT_MEMORY_POLICY; } /* Check this allocation failure is caused by cpuset's wall function */ for_each_zone_zonelist_nodemask(zone, z, zonelist, high_zoneidx, nodemask) if (!cpuset_zone_allowed_softwall(zone, gfp_mask)) cpuset_limited = true; if (cpuset_limited) { *totalpages = total_swap_pages; for_each_node_mask(nid, cpuset_current_mems_allowed) *totalpages += node_spanned_pages(nid); return CONSTRAINT_CPUSET; } return CONSTRAINT_NONE;}#elsestatic enum oom_constraint constrained_alloc(struct zonelist *zonelist, gfp_t gfp_mask, nodemask_t *nodemask, unsigned long *totalpages){ *totalpages = totalram_pages + total_swap_pages; return CONSTRAINT_NONE;}#endif enum oom_scan_t oom_scan_process_thread(struct task_struct *task, unsigned long totalpages, const nodemask_t *nodemask, bool force_kill){ if (task->exit_state) return OOM_SCAN_CONTINUE; if (oom_unkillable_task(task, NULL, nodemask)) return OOM_SCAN_CONTINUE; /* * This task already has access to memory reserves and is being killed. * Don't allow any other task to have access to the reserves. */ if (test_tsk_thread_flag(task, TIF_MEMDIE)) { if (unlikely(frozen(task))) __thaw_task(task); if (!force_kill) return OOM_SCAN_ABORT; } 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 * to finish before killing some other task unnecessarily. */ if (!(task->group_leader->ptrace & PT_TRACE_EXIT)) return OOM_SCAN_ABORT; } return OOM_SCAN_OK;} /* * Simple selection loop. We chose the process with the highest * number of 'points'. Returns -1 on scan abort. * * (not docbooked, we don't want this one cluttering up the manual) */static struct task_struct *select_bad_process(unsigned int *ppoints, unsigned long totalpages, const nodemask_t *nodemask, bool force_kill){ struct task_struct *g, *p; struct task_struct *chosen = NULL; unsigned long chosen_points = 0; rcu_read_lock(); do_each_thread(g, p) { unsigned int points; switch (oom_scan_process_thread(p, totalpages, nodemask, force_kill)) { case OOM_SCAN_SELECT: chosen = p; chosen_points = ULONG_MAX; /* fall through */ case OOM_SCAN_CONTINUE: continue; case OOM_SCAN_ABORT: rcu_read_unlock(); return (struct task_struct *)(-1UL); case OOM_SCAN_OK: break; }; points = oom_badness(p, NULL, nodemask, totalpages); if (points > chosen_points) { chosen = p; chosen_points = points; } } while_each_thread(g, p); if (chosen) get_task_struct(chosen); rcu_read_unlock(); *ppoints = chosen_points * 1000 / totalpages; return chosen;} /** * dump_tasks - dump current memory state of all system tasks * @memcg: current's memory controller, if constrained * @nodemask: nodemask passed to page allocator for mempolicy ooms * * Dumps the current memory state of all eligible tasks. Tasks not in the same * memcg, not in the same cpuset, or bound to a disjoint set of mempolicy nodes * are not shown. * State information includes task's pid, uid, tgid, vm size, rss, nr_ptes, * swapents, oom_score_adj value, and name. */static void dump_tasks(const struct mem_cgroup *memcg, const nodemask_t *nodemask){ struct task_struct *p; struct task_struct *task; pr_info("[ pid ] uid tgid total_vm rss nr_ptes swapents oom_score_adj name\n"); rcu_read_lock(); for_each_process(p) { if (oom_unkillable_task(p, memcg, nodemask)) continue; task = find_lock_task_mm(p); if (!task) { /* * This is a kthread or all of p's threads have already * detached their mm's. There's no need to report * them; they can't be oom killed anyway. */ continue; } pr_info("[%5d] %5d %5d %8lu %8lu %7ld %8lu %5hd %s\n", task->pid, from_kuid(&init_user_ns, task_uid(task)), task->tgid, task->mm->total_vm, get_mm_rss(task->mm), atomic_long_read(&task->mm->nr_ptes), get_mm_counter(task->mm, MM_SWAPENTS), task->signal->oom_score_adj, task->comm); task_unlock(task); } rcu_read_unlock();} static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order, struct mem_cgroup *memcg, const nodemask_t *nodemask){ task_lock(current); pr_warning("%s invoked oom-killer: gfp_mask=0x%x, order=%d, " "oom_score_adj=%hd\n", current->comm, gfp_mask, order, current->signal->oom_score_adj); cpuset_print_task_mems_allowed(current); task_unlock(current); dump_stack(); if (memcg) mem_cgroup_print_oom_info(memcg, p); else show_mem(SHOW_MEM_FILTER_NODES); if (sysctl_oom_dump_tasks) dump_tasks(memcg, nodemask);} #define K(x) ((x) << (PAGE_SHIFT-10))/* * Must be called while holding a reference to p, which will be released upon * returning. */void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, unsigned int points, unsigned long totalpages, struct mem_cgroup *memcg, nodemask_t *nodemask, const char *message){ struct task_struct *victim = p; struct task_struct *child; struct task_struct *t = p; struct mm_struct *mm; unsigned int victim_points = 0; static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); /* * If the task is already exiting, don't alarm the sysadmin or kill * its children or threads, just set TIF_MEMDIE so it can die quickly */ if (p->flags & PF_EXITING) { set_tsk_thread_flag(p, TIF_MEMDIE); put_task_struct(p); return; } if (__ratelimit(&oom_rs)) dump_header(p, gfp_mask, order, memcg, nodemask); task_lock(p); pr_err("%s: Kill process %d (%s) score %d or sacrifice child\n", message, task_pid_nr(p), p->comm, points); task_unlock(p); /* * If any of p's children has a different mm and is eligible for kill, * the one with the highest oom_badness() score is sacrificed for its * parent. This attempts to lose the minimal amount of work done while * still freeing memory. */ read_lock(&tasklist_lock); do { list_for_each_entry(child, &t->children, sibling) { unsigned int child_points; if (child->mm == p->mm) continue; /* * oom_badness() returns 0 if the thread is unkillable */ child_points = oom_badness(child, memcg, nodemask, totalpages); if (child_points > victim_points) { put_task_struct(victim); victim = child; victim_points = child_points; get_task_struct(victim); } } } while_each_thread(p, t); read_unlock(&tasklist_lock); rcu_read_lock(); p = find_lock_task_mm(victim); if (!p) { rcu_read_unlock(); put_task_struct(victim); return; } else if (victim != p) { get_task_struct(p); put_task_struct(victim); victim = p; } /* mm cannot safely be dereferenced after task_unlock(victim) */ mm = victim->mm; pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB\n", task_pid_nr(victim), victim->comm, K(victim->mm->total_vm), K(get_mm_counter(victim->mm, MM_ANONPAGES)), K(get_mm_counter(victim->mm, MM_FILEPAGES))); task_unlock(victim); /* * Kill all user processes sharing victim->mm in other thread groups, if * any. They don't get access to memory reserves, though, to avoid * depletion of all memory. This prevents mm->mmap_sem livelock when an * oom killed thread cannot exit because it requires the semaphore and * its contended by another thread trying to allocate memory itself. * That thread will now get access to memory reserves since it has a * pending fatal signal. */ for_each_process(p) if (p->mm == mm && !same_thread_group(p, victim) && !(p->flags & PF_KTHREAD)) { if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) continue; task_lock(p); /* Protect ->comm from prctl() */ pr_err("Kill process %d (%s) sharing same memory\n", task_pid_nr(p), p->comm); task_unlock(p); do_send_sig_info(SIGKILL, SEND_SIG_FORCED, p, true);Lines 1–500 of 691. Load more
/* * linux/mm/oom_kill.c * * Copyright (C) 1998,2000 Rik van Riel * Thanks go out to Claus Fischer for some serious inspiration and * for goading me into coding this file... * Copyright (C) 2010 Google, Inc. * Rewritten by David Rientjes * * The routines in this file are used to kill a process when * we're seriously out of memory. This gets called from __alloc_pages() * in mm/page_alloc.c when we really run out of memory. * * Since we won't call these routines often (on a well-configured * machine) this file will double as a 'coding guide' and a signpost * for newbie kernel hackers. It features several pointers to major * kernel subsystems and hints as to where to find out what things do. */ #include <linux/oom.h> #include <linux/mm.h> #include <linux/err.h> #include <linux/gfp.h> #include <linux/sched.h> #include <linux/swap.h> #include <linux/timex.h> #include <linux/jiffies.h> #include <linux/cpuset.h> #include <linux/export.h> #include <linux/notifier.h> #include <linux/memcontrol.h> #include <linux/mempolicy.h> #include <linux/security.h> #include <linux/ptrace.h> #include <linux/freezer.h> #include <linux/ftrace.h> #include <linux/ratelimit.h> #define CREATE_TRACE_POINTS #include <trace/events/oom.h> int sysctl_panic_on_oom; int sysctl_oom_kill_allocating_task; int sysctl_oom_dump_tasks = 1; static DEFINE_SPINLOCK(zone_scan_lock); #ifdef CONFIG_NUMA /** * has_intersects_mems_allowed() - check task eligiblity for kill * @tsk: task struct of which task to consider * @mask: nodemask passed to page allocator for mempolicy ooms * * Task eligibility is determined by whether or not a candidate task, @tsk, * shares the same mempolicy nodes as current if it is bound by such a policy * and whether or not it has the same set of allowed cpuset nodes. */ static bool has_intersects_mems_allowed(struct task_struct *tsk, const nodemask_t *mask) { struct task_struct *start = tsk; do { if (mask) { /* * If this is a mempolicy constrained oom, tsk's * cpuset is irrelevant. Only return true if its * mempolicy intersects current, otherwise it may be * needlessly killed. */ if (mempolicy_nodemask_intersects(tsk, mask)) return true; } else { /* * This is not a mempolicy constrained oom, so only * check the mems of tsk's cpuset. */ if (cpuset_mems_allowed_intersects(current, tsk)) return true; } } while_each_thread(start, tsk); return false; } #else static bool has_intersects_mems_allowed(struct task_struct *tsk, const nodemask_t *mask) { return true; } #endif /* CONFIG_NUMA */ /* * The process p may have detached its own ->mm while exiting or through * use_mm(), but one or more of its subthreads may still have a valid * pointer. Return p, or any of its subthreads with a valid ->mm, with * task_lock() held. */ struct task_struct *find_lock_task_mm(struct task_struct *p) { struct task_struct *t = p; do { task_lock(t); if (likely(t->mm)) return t; task_unlock(t); } while_each_thread(p, t); return NULL; } /* return true if the task is not adequate as candidate victim task. */ static bool oom_unkillable_task(struct task_struct *p, const struct mem_cgroup *memcg, const nodemask_t *nodemask) { if (is_global_init(p)) return true; if (p->flags & PF_KTHREAD) return true; /* When mem_cgroup_out_of_memory() and p is not member of the group */ if (memcg && !task_in_mem_cgroup(p, memcg)) return true; /* p may not have freeable memory in nodemask */ if (!has_intersects_mems_allowed(p, nodemask)) return true; return false; } /** * oom_badness - heuristic function to determine which candidate task to kill * @p: task struct of which task we should calculate * @totalpages: total present RAM allowed for page allocation * * The heuristic for determining which task to kill is made to be as simple and * predictable as possible. The goal is to return the highest value for the * task consuming the most memory to avoid subsequent oom failures. */ unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg, const nodemask_t *nodemask, unsigned long totalpages) { long points; long adj; if (oom_unkillable_task(p, memcg, nodemask)) return 0; p = find_lock_task_mm(p); if (!p) return 0; adj = (long)p->signal->oom_score_adj; if (adj == OOM_SCORE_ADJ_MIN) { task_unlock(p); return 0; } /* * The baseline for the badness score is the proportion of RAM that each * task's rss, pagetable and swap space use. */ points = get_mm_rss(p->mm) + atomic_long_read(&p->mm->nr_ptes) + get_mm_counter(p->mm, MM_SWAPENTS); task_unlock(p); /* * Root processes get 3% bonus, just like the __vm_enough_memory() * implementation used by LSMs. */ if (has_capability_noaudit(p, CAP_SYS_ADMIN)) adj -= 30; /* Normalize to oom_score_adj units */ adj *= totalpages / 1000; points += adj; /* * Never return 0 for an eligible task regardless of the root bonus and * oom_score_adj (oom_score_adj can't be OOM_SCORE_ADJ_MIN here). */ return points > 0 ? points : 1; } /* * Determine the type of allocation constraint. */ #ifdef CONFIG_NUMA static enum oom_constraint constrained_alloc(struct zonelist *zonelist, gfp_t gfp_mask, nodemask_t *nodemask, unsigned long *totalpages) { struct zone *zone; struct zoneref *z; enum zone_type high_zoneidx = gfp_zone(gfp_mask); bool cpuset_limited = false; int nid; /* Default to all available memory */ *totalpages = totalram_pages + total_swap_pages; if (!zonelist) return CONSTRAINT_NONE; /* * Reach here only when __GFP_NOFAIL is used. So, we should avoid * to kill current.We have to random task kill in this case. * Hopefully, CONSTRAINT_THISNODE...but no way to handle it, now. */ if (gfp_mask & __GFP_THISNODE) return CONSTRAINT_NONE; /* * This is not a __GFP_THISNODE allocation, so a truncated nodemask in * the page allocator means a mempolicy is in effect. Cpuset policy * is enforced in get_page_from_freelist(). */ if (nodemask && !nodes_subset(node_states[N_MEMORY], *nodemask)) { *totalpages = total_swap_pages; for_each_node_mask(nid, *nodemask) *totalpages += node_spanned_pages(nid); return CONSTRAINT_MEMORY_POLICY; } /* Check this allocation failure is caused by cpuset's wall function */ for_each_zone_zonelist_nodemask(zone, z, zonelist, high_zoneidx, nodemask) if (!cpuset_zone_allowed_softwall(zone, gfp_mask)) cpuset_limited = true; if (cpuset_limited) { *totalpages = total_swap_pages; for_each_node_mask(nid, cpuset_current_mems_allowed) *totalpages += node_spanned_pages(nid); return CONSTRAINT_CPUSET; } return CONSTRAINT_NONE; } #else static enum oom_constraint constrained_alloc(struct zonelist *zonelist, gfp_t gfp_mask, nodemask_t *nodemask, unsigned long *totalpages) { *totalpages = totalram_pages + total_swap_pages; return CONSTRAINT_NONE; } #endif enum oom_scan_t oom_scan_process_thread(struct task_struct *task, unsigned long totalpages, const nodemask_t *nodemask, bool force_kill) { if (task->exit_state) return OOM_SCAN_CONTINUE; if (oom_unkillable_task(task, NULL, nodemask)) return OOM_SCAN_CONTINUE; /* * This task already has access to memory reserves and is being killed. * Don't allow any other task to have access to the reserves. */ if (test_tsk_thread_flag(task, TIF_MEMDIE)) { if (unlikely(frozen(task))) __thaw_task(task); if (!force_kill) return OOM_SCAN_ABORT; } 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 * to finish before killing some other task unnecessarily. */ if (!(task->group_leader->ptrace & PT_TRACE_EXIT)) return OOM_SCAN_ABORT; } return OOM_SCAN_OK; } /* * Simple selection loop. We chose the process with the highest * number of 'points'. Returns -1 on scan abort. * * (not docbooked, we don't want this one cluttering up the manual) */ static struct task_struct *select_bad_process(unsigned int *ppoints, unsigned long totalpages, const nodemask_t *nodemask, bool force_kill) { struct task_struct *g, *p; struct task_struct *chosen = NULL; unsigned long chosen_points = 0; rcu_read_lock(); do_each_thread(g, p) { unsigned int points; switch (oom_scan_process_thread(p, totalpages, nodemask, force_kill)) { case OOM_SCAN_SELECT: chosen = p; chosen_points = ULONG_MAX; /* fall through */ case OOM_SCAN_CONTINUE: continue; case OOM_SCAN_ABORT: rcu_read_unlock(); return (struct task_struct *)(-1UL); case OOM_SCAN_OK: break; }; points = oom_badness(p, NULL, nodemask, totalpages); if (points > chosen_points) { chosen = p; chosen_points = points; } } while_each_thread(g, p); if (chosen) get_task_struct(chosen); rcu_read_unlock(); *ppoints = chosen_points * 1000 / totalpages; return chosen; } /** * dump_tasks - dump current memory state of all system tasks * @memcg: current's memory controller, if constrained * @nodemask: nodemask passed to page allocator for mempolicy ooms * * Dumps the current memory state of all eligible tasks. Tasks not in the same * memcg, not in the same cpuset, or bound to a disjoint set of mempolicy nodes * are not shown. * State information includes task's pid, uid, tgid, vm size, rss, nr_ptes, * swapents, oom_score_adj value, and name. */ static void dump_tasks(const struct mem_cgroup *memcg, const nodemask_t *nodemask) { struct task_struct *p; struct task_struct *task; pr_info("[ pid ] uid tgid total_vm rss nr_ptes swapents oom_score_adj name\n"); rcu_read_lock(); for_each_process(p) { if (oom_unkillable_task(p, memcg, nodemask)) continue; task = find_lock_task_mm(p); if (!task) { /* * This is a kthread or all of p's threads have already * detached their mm's. There's no need to report * them; they can't be oom killed anyway. */ continue; } pr_info("[%5d] %5d %5d %8lu %8lu %7ld %8lu %5hd %s\n", task->pid, from_kuid(&init_user_ns, task_uid(task)), task->tgid, task->mm->total_vm, get_mm_rss(task->mm), atomic_long_read(&task->mm->nr_ptes), get_mm_counter(task->mm, MM_SWAPENTS), task->signal->oom_score_adj, task->comm); task_unlock(task); } rcu_read_unlock(); } static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order, struct mem_cgroup *memcg, const nodemask_t *nodemask) { task_lock(current); pr_warning("%s invoked oom-killer: gfp_mask=0x%x, order=%d, " "oom_score_adj=%hd\n", current->comm, gfp_mask, order, current->signal->oom_score_adj); cpuset_print_task_mems_allowed(current); task_unlock(current); dump_stack(); if (memcg) mem_cgroup_print_oom_info(memcg, p); else show_mem(SHOW_MEM_FILTER_NODES); if (sysctl_oom_dump_tasks) dump_tasks(memcg, nodemask); } #define K(x) ((x) << (PAGE_SHIFT-10)) /* * Must be called while holding a reference to p, which will be released upon * returning. */ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, unsigned int points, unsigned long totalpages, struct mem_cgroup *memcg, nodemask_t *nodemask, const char *message) { struct task_struct *victim = p; struct task_struct *child; struct task_struct *t = p; struct mm_struct *mm; unsigned int victim_points = 0; static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); /* * If the task is already exiting, don't alarm the sysadmin or kill * its children or threads, just set TIF_MEMDIE so it can die quickly */ if (p->flags & PF_EXITING) { set_tsk_thread_flag(p, TIF_MEMDIE); put_task_struct(p); return; } if (__ratelimit(&oom_rs)) dump_header(p, gfp_mask, order, memcg, nodemask); task_lock(p); pr_err("%s: Kill process %d (%s) score %d or sacrifice child\n", message, task_pid_nr(p), p->comm, points); task_unlock(p); /* * If any of p's children has a different mm and is eligible for kill, * the one with the highest oom_badness() score is sacrificed for its * parent. This attempts to lose the minimal amount of work done while * still freeing memory. */ read_lock(&tasklist_lock); do { list_for_each_entry(child, &t->children, sibling) { unsigned int child_points; if (child->mm == p->mm) continue; /* * oom_badness() returns 0 if the thread is unkillable */ child_points = oom_badness(child, memcg, nodemask, totalpages); if (child_points > victim_points) { put_task_struct(victim); victim = child; victim_points = child_points; get_task_struct(victim); } } } while_each_thread(p, t); read_unlock(&tasklist_lock); rcu_read_lock(); p = find_lock_task_mm(victim); if (!p) { rcu_read_unlock(); put_task_struct(victim); return; } else if (victim != p) { get_task_struct(p); put_task_struct(victim); victim = p; } /* mm cannot safely be dereferenced after task_unlock(victim) */ mm = victim->mm; pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB\n", task_pid_nr(victim), victim->comm, K(victim->mm->total_vm), K(get_mm_counter(victim->mm, MM_ANONPAGES)), K(get_mm_counter(victim->mm, MM_FILEPAGES))); task_unlock(victim); /* * Kill all user processes sharing victim->mm in other thread groups, if * any. They don't get access to memory reserves, though, to avoid * depletion of all memory. This prevents mm->mmap_sem livelock when an * oom killed thread cannot exit because it requires the semaphore and * its contended by another thread trying to allocate memory itself. * That thread will now get access to memory reserves since it has a * pending fatal signal. */ for_each_process(p) if (p->mm == mm && !same_thread_group(p, victim) && !(p->flags & PF_KTHREAD)) { if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) continue; task_lock(p); /* Protect ->comm from prctl() */ pr_err("Kill process %d (%s) sharing same memory\n", task_pid_nr(p), p->comm); task_unlock(p); do_send_sig_info(SIGKILL, SEND_SIG_FORCED, p, true);