From: Jing Xiangfeng <jingxiangfeng@huawei.com> hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I3ZN3O CVE: NA -------------------------------------- This patch adds sysctl memcg_qos_enable to enable/disable memcg priority feature. If you want to enable it by writing 1: echo 1 > /proc/sys/vm/memcg_qos_enable Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com> Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> --- include/linux/memcontrol.h | 3 ++ mm/memcontrol.c | 79 ++++++++++++++++++++++++++++++++++++++ mm/oom_kill.c | 3 ++ 3 files changed, 85 insertions(+) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 62e77ce8a6f4..2946186ac3ef 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -346,9 +346,12 @@ struct mem_cgroup { #ifdef CONFIG_MEMCG_OOM_PRIORITY #define MEMCG_LOW_OOM_PRIORITY -1 #define MEMCG_HIGH_OOM_PRIORITY 0 +extern int sysctl_memcg_oom_prio; + bool memcg_oom_prio_scan_tasks(int (*)(struct task_struct *, void *), void *); void memcg_print_bad_task(struct oom_control *oc); +bool memcg_oom_prio_disabled(void); #else static inline void memcg_print_bad_task(struct oom_control *oc) { diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c06414ee9007..0c270f20c368 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3966,6 +3966,15 @@ static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, #endif #ifdef CONFIG_MEMCG_OOM_PRIORITY +#define ENABLE_MEMCG_OOM_PROIRITY 1 +#define DISABLE_MEMCG_OOM_PROIRITY 0 +int sysctl_memcg_oom_prio = DISABLE_MEMCG_OOM_PROIRITY; + +bool memcg_oom_prio_disabled(void) +{ + return READ_ONCE(sysctl_memcg_oom_prio) == DISABLE_MEMCG_OOM_PROIRITY; +} + static void memcg_oom_prio_init(struct mem_cgroup *memcg) { struct mem_cgroup *parent = parent_mem_cgroup(memcg); @@ -4000,6 +4009,9 @@ static s64 memcg_oom_prio_read(struct cgroup_subsys_state *css, { struct mem_cgroup *memcg = mem_cgroup_from_css(css); + if (memcg_oom_prio_disabled()) + return 0; + return READ_ONCE(memcg->oom_prio); } @@ -4008,6 +4020,9 @@ static int memcg_oom_prio_write(struct cgroup_subsys_state *css, { struct mem_cgroup *memcg = mem_cgroup_from_css(css); + if (memcg_oom_prio_disabled()) + return -EACCES; + if (mem_cgroup_is_root(memcg)) return -EINVAL; @@ -4058,6 +4073,8 @@ bool memcg_oom_prio_scan_tasks(int (*fn)(struct task_struct *, void *), int ret = 0; bool retry = true; + if (memcg_oom_prio_disabled()) + return false; retry: max = memcg_find_max_usage(last); if (!max) @@ -4090,6 +4107,9 @@ bool memcg_oom_prio_scan_tasks(int (*fn)(struct task_struct *, void *), void memcg_print_bad_task(struct oom_control *oc) { + if (memcg_oom_prio_disabled()) + return; + if (oc->chosen) { struct mem_cgroup *memcg; @@ -4099,6 +4119,65 @@ void memcg_print_bad_task(struct oom_control *oc) oc->chosen->pid, oc->chosen->comm); } } + +static void memcg_oom_prio_reset(void) +{ + struct mem_cgroup *iter; + struct cgroup_subsys_state *css; + + rcu_read_lock(); + css_for_each_descendant_pre(css, &root_mem_cgroup->css) { + iter = mem_cgroup_from_css(css); + WRITE_ONCE(iter->oom_prio, 0); + } + rcu_read_unlock(); +} + +static int sysctl_memcg_oom_prio_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *length, loff_t *ppos) +{ + int ret; + + ret = proc_dointvec_minmax(table, write, buffer, length, ppos); + if (ret) + return ret; + + if (write) { + if (READ_ONCE(sysctl_memcg_oom_prio) == ENABLE_MEMCG_OOM_PROIRITY) { + pr_info("enable memcg priority.\n"); + } else { + memcg_oom_prio_reset(); + pr_info("disable memcg priority.\n"); + } + } + + return ret; +} + +static struct ctl_table memcg_oom_prio_sysctls[] = { + { + /* + * This sysctl is used to control memcg oom priority + * feature, the sysctl name is for compatibility. + */ + .procname = "memcg_qos_enable", + .data = &sysctl_memcg_oom_prio, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = sysctl_memcg_oom_prio_handler, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + {} +}; + +static __init int memcg_oom_prio_sysctls_init(void) +{ + register_sysctl_init("vm", memcg_oom_prio_sysctls); + return 0; +} +late_initcall(memcg_oom_prio_sysctls_init); + #endif #ifdef CONFIG_NUMA diff --git a/mm/oom_kill.c b/mm/oom_kill.c index d024f19082a6..c1a8f96cefc0 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -317,6 +317,9 @@ static bool oom_next_task(struct task_struct *task, struct oom_control *oc, struct mem_cgroup *oc_memcg; int cur_memcg_prio, oc_memcg_prio; + if (memcg_oom_prio_disabled()) + return points == LONG_MIN || points < oc->chosen_points; + if (points == LONG_MIN) return true; -- 2.25.1