Commit 44391f31 authored by Jing Xiangfeng's avatar Jing Xiangfeng Committed by Jinjiang Tu
Browse files

memcg: Add sysctl memcg_qos_enable 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8PXX8


CVE: NA

--------------------------------------

This patch adds sysctl memcg_qos_enable to enable/disable
memcg oom priority feature. If you want to enable it by writing 1:

echo 1 > /proc/sys/vm/memcg_qos_enable

Signed-off-by: default avatarJing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: default avatarJinjiang Tu <tujinjiang@huawei.com>
parent be8d9553

include/linux/memcontrol.h

+1 −0
Original line number Diff line number Diff line
@@ -360,6 +360,7 @@ struct mem_cgroup { 
bool memcg_oom_prio_scan_tasks(int (*fn)(struct task_struct *, void *),

				   void *arg);

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)

{

mm/memcontrol.c

+79 −0
Original line number Diff line number Diff line
@@ -4056,6 +4056,15 @@ 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);
@@ -4073,6 +4082,9 @@ 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);

}
@@ -4083,6 +4095,9 @@ static int memcg_oom_prio_write(struct cgroup_subsys_state *css, 
	struct mem_cgroup *iter_memcg;

	struct cgroup_subsys_state *iter_css;



	if (memcg_oom_prio_disabled())

		return -EACCES;



	if (mem_cgroup_is_root(memcg))

		return -EINVAL;
@@ -4138,6 +4153,8 @@ 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)
@@ -4170,6 +4187,9 @@ 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;
@@ -4181,6 +4201,64 @@ void memcg_print_bad_task(struct oom_control *oc) 
		rcu_read_unlock();

	}

}



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) == DISABLE_MEMCG_OOM_PROIRITY)

			memcg_oom_prio_reset();

	}



	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;

}

#else

static inline int memcg_oom_prio_sysctls_init(void)

{

	return 0;

}



#endif



#ifdef CONFIG_NUMA
@@ -7951,6 +8029,7 @@ static int __init mem_cgroup_init(void) 
	}



	mem_cgroup_memfs_info_init();

	memcg_oom_prio_sysctls_init();



	return 0;

}

mm/oom_kill.c

+3 −0
Original line number Diff line number Diff line
@@ -318,6 +318,9 @@ 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;