diff options
| -rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 18 | ||||
| -rw-r--r-- | include/linux/memcontrol.h | 18 | ||||
| -rw-r--r-- | mm/memcontrol.c | 93 | ||||
| -rw-r--r-- | mm/oom_kill.c | 30 |
4 files changed, 159 insertions, 0 deletions
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 1746131bc9cb..184193bcb262 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1072,6 +1072,24 @@ PAGE_SIZE multiple when read back. high limit is used and monitored properly, this limit's utility is limited to providing the final safety net. + memory.oom.group + A read-write single value file which exists on non-root + cgroups. The default value is "0". + + Determines whether the cgroup should be treated as + an indivisible workload by the OOM killer. If set, + all tasks belonging to the cgroup or to its descendants + (if the memory cgroup is not a leaf cgroup) are killed + together or not at all. This can be used to avoid + partial kills to guarantee workload integrity. + + Tasks with the OOM protection (oom_score_adj set to -1000) + are treated as an exception and are never killed. + + If the OOM killer is invoked in a cgroup, it's not going + to kill any tasks outside of this cgroup, regardless + memory.oom.group values of ancestor cgroups. + memory.events A read-only flat-keyed file which exists on non-root cgroups. The following entries are defined. Unless specified diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 0e6c515fb698..652f602167df 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -225,6 +225,11 @@ struct mem_cgroup { */ bool use_hierarchy; + /* + * Should the OOM killer kill all belonging tasks, had it kill one? + */ + bool oom_group; + /* protected by memcg_oom_lock */ bool oom_lock; int under_oom; @@ -542,6 +547,9 @@ static inline bool task_in_memcg_oom(struct task_struct *p) } bool mem_cgroup_oom_synchronize(bool wait); +struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim, + struct mem_cgroup *oom_domain); +void mem_cgroup_print_oom_group(struct mem_cgroup *memcg); #ifdef CONFIG_MEMCG_SWAP extern int do_swap_account; @@ -1001,6 +1009,16 @@ static inline bool mem_cgroup_oom_synchronize(bool wait) return false; } +static inline struct mem_cgroup *mem_cgroup_get_oom_group( + struct task_struct *victim, struct mem_cgroup *oom_domain) +{ + return NULL; +} + +static inline void mem_cgroup_print_oom_group(struct mem_cgroup *memcg) +{ +} + static inline unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx) { diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 59c14c988143..4ead5a4817de 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1777,6 +1777,62 @@ cleanup: } /** + * mem_cgroup_get_oom_group - get a memory cgroup to clean up after OOM + * @victim: task to be killed by the OOM killer + * @oom_domain: memcg in case of memcg OOM, NULL in case of system-wide OOM + * + * Returns a pointer to a memory cgroup, which has to be cleaned up + * by killing all belonging OOM-killable tasks. + * + * Caller has to call mem_cgroup_put() on the returned non-NULL memcg. + */ +struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim, + struct mem_cgroup *oom_domain) +{ + struct mem_cgroup *oom_group = NULL; + struct mem_cgroup *memcg; + + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) + return NULL; + + if (!oom_domain) + oom_domain = root_mem_cgroup; + + rcu_read_lock(); + + memcg = mem_cgroup_from_task(victim); + if (memcg == root_mem_cgroup) + goto out; + + /* + * Traverse the memory cgroup hierarchy from the victim task's + * cgroup up to the OOMing cgroup (or root) to find the + * highest-level memory cgroup with oom.group set. + */ + for (; memcg; memcg = parent_mem_cgroup(memcg)) { + if (memcg->oom_group) + oom_group = memcg; + + if (memcg == oom_domain) + break; + } + + if (oom_group) + css_get(&oom_group->css); +out: + rcu_read_unlock(); + + return oom_group; +} + +void mem_cgroup_print_oom_group(struct mem_cgroup *memcg) +{ + pr_info("Tasks in "); + pr_cont_cgroup_path(memcg->css.cgroup); + pr_cont(" are going to be killed due to memory.oom.group set\n"); +} + +/** * lock_page_memcg - lock a page->mem_cgroup binding * @page: the page * @@ -5561,6 +5617,37 @@ static int memory_stat_show(struct seq_file *m, void *v) return 0; } +static int memory_oom_group_show(struct seq_file *m, void *v) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); + + seq_printf(m, "%d\n", memcg->oom_group); + + return 0; +} + +static ssize_t memory_oom_group_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); + int ret, oom_group; + + buf = strstrip(buf); + if (!buf) + return -EINVAL; + + ret = kstrtoint(buf, 0, &oom_group); + if (ret) + return ret; + + if (oom_group != 0 && oom_group != 1) + return -EINVAL; + + memcg->oom_group = oom_group; + + return nbytes; +} + static struct cftype memory_files[] = { { .name = "current", @@ -5602,6 +5689,12 @@ static struct cftype memory_files[] = { .flags = CFTYPE_NOT_ON_ROOT, .seq_show = memory_stat_show, }, + { + .name = "oom.group", + .flags = CFTYPE_NOT_ON_ROOT | CFTYPE_NS_DELEGATABLE, + .seq_show = memory_oom_group_show, + .write = memory_oom_group_write, + }, { } /* terminate */ }; diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 330416c67ce5..0e10b864e074 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -908,6 +908,19 @@ static void __oom_kill_process(struct task_struct *victim) } #undef K +/* + * Kill provided task unless it's secured by setting + * oom_score_adj to OOM_SCORE_ADJ_MIN. + */ +static int oom_kill_memcg_member(struct task_struct *task, void *unused) +{ + if (task->signal->oom_score_adj != OOM_SCORE_ADJ_MIN) { + get_task_struct(task); + __oom_kill_process(task); + } + return 0; +} + static void oom_kill_process(struct oom_control *oc, const char *message) { struct task_struct *p = oc->chosen; @@ -915,6 +928,7 @@ static void oom_kill_process(struct oom_control *oc, const char *message) struct task_struct *victim = p; struct task_struct *child; struct task_struct *t; + struct mem_cgroup *oom_group; unsigned int victim_points = 0; static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); @@ -968,7 +982,23 @@ static void oom_kill_process(struct oom_control *oc, const char *message) } read_unlock(&tasklist_lock); + /* + * Do we need to kill the entire memory cgroup? + * Or even one of the ancestor memory cgroups? + * Check this out before killing the victim task. + */ + oom_group = mem_cgroup_get_oom_group(victim, oc->memcg); + __oom_kill_process(victim); + + /* + * If necessary, kill all tasks in the selected memory cgroup. + */ + if (oom_group) { + mem_cgroup_print_oom_group(oom_group); + mem_cgroup_scan_tasks(oom_group, oom_kill_memcg_member, NULL); + mem_cgroup_put(oom_group); + } } /* |