diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 1746131bc9cb315dca4d4b03b23678cece518727..184193bcb262ac908f1f5a7a7c2c662dec0ea4b8 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 0e6c515fb698f7a6e8c139b2fc87b9286342ca06..652f602167df49b58830acca591e3fbe5fb67185 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 59c14c988143b2ce6cfe4b90fc6bf6c2ff564be5..4ead5a4817de3ffbf1477cfe77b8f4f4802281c8 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1776,6 +1776,62 @@ bool mem_cgroup_oom_synchronize(bool handle)
return true;
}
+/**
+ * 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 330416c67ce52391ebc18727f5e917064f3a9c5f..0e10b864e0742da9f545130dbd913e1e8c7a8efb 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);
+ }
}
/*