Commit bebf0cae authored by Ze Zuo's avatar Ze Zuo
Browse files

mm/mem_sampling.c: Add controlling interface for mem_sampling on numa balance 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9GZAQ


CVE: NA

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

Add sysctl to enable or disable mem_sampling actions for numa_balance.

A static key controlled by sysctl is added. When this is set to
false, numa balance will use the native prot_none scheme, and
when set to true, it will use hardware sampling instead of the native
scheme.

Signed-off-by: default avatarZe Zuo <zuoze1@huawei.com>
parent bdc47013

mm/mem_sampling.c

+59 −0
Original line number Diff line number Diff line
@@ -27,6 +27,8 @@ struct mem_sampling_ops_struct mem_sampling_ops; 


#define MEM_SAMPLING_DISABLED		0x0

#define MEM_SAMPLING_NORMAL		0x1

#define NUMA_BALANCING_HW_DISABLED	0x0

#define NUMA_BALANCING_HW_NORMAL	0x1



static int mem_sampling_override __initdata;

struct mem_sampling_record_cb_list_entry {
@@ -279,6 +281,49 @@ static inline enum mem_sampling_type_enum mem_sampling_get_type(void) 


DEFINE_STATIC_KEY_FALSE(sched_numabalancing_mem_sampling);



#ifdef CONFIG_NUMABALANCING_MEM_SAMPLING



static void set_numabalancing_mem_sampling_state(bool enabled)

{

	if (enabled) {

		numa_balancing_mem_sampling_cb_register();

		static_branch_enable(&sched_numabalancing_mem_sampling);

	} else {

		numa_balancing_mem_sampling_cb_unregister();

		static_branch_disable(&sched_numabalancing_mem_sampling);

	}

}



#ifdef CONFIG_PROC_SYSCTL

int sysctl_numabalancing_mem_sampling(struct ctl_table *table, int write,

				void *buffer, size_t *lenp, loff_t *ppos)

{

	struct ctl_table t;

	int err;

	int state = static_branch_likely(&sched_numabalancing_mem_sampling);



	if (write && !capable(CAP_SYS_ADMIN))

		return -EPERM;



	t = *table;

	t.data = &state;

	err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos);

	if (err < 0)

		return err;



	if (write && static_branch_likely(&mem_sampling_access_hints))

		set_numabalancing_mem_sampling_state(state);



	return err;

}

#endif

#else

static inline void set_numabalancing_mem_sampling_state(bool enabled)

{



}

#endif



static int sysctl_mem_sampling_mode;



static void __set_mem_sampling_state(bool enabled)
@@ -298,6 +343,9 @@ static void set_mem_sampling_state(bool enabled) 
	else

		sysctl_mem_sampling_mode = MEM_SAMPLING_DISABLED;

	__set_mem_sampling_state(enabled);



	if (!enabled)

		set_numabalancing_mem_sampling_state(enabled);

}



#ifdef CONFIG_PROC_SYSCTL
@@ -332,6 +380,17 @@ static struct ctl_table ctl_table[] = { 
		.extra1		= SYSCTL_ZERO,

		.extra2		= SYSCTL_ONE,

	},

#ifdef CONFIG_NUMABALANCING_MEM_SAMPLING

	{

		.procname	= "numa_balancing_mem_sampling",

		.data		= NULL, /* filled in by handler */

		.maxlen		= sizeof(unsigned int),

		.mode		= 0644,

		.proc_handler	= sysctl_numabalancing_mem_sampling,

		.extra1		= SYSCTL_ZERO,

		.extra2		= SYSCTL_ONE,

	},

#endif /* CONFIG_NUMABALANCING_MEM_SAMPLING */

	{}

};