linux/kernel/cgroup/cpuset-internal.h

/* SPDX-License-Identifier: GPL-2.0-or-later */

#ifndef __CPUSET_INTERNAL_H
#define __CPUSET_INTERNAL_H

#include <linux/union_find.h>
#include <linux/cpumask.h>
#include <linux/spinlock.h>
#include <linux/cpuset.h>
#include <linux/cgroup.h>

/* See "Frequency meter" comments, below. */

struct fmeter {
	int cnt;		/* unprocessed events count */
	int val;		/* most recent output value */
	time64_t time;		/* clock (secs) when val computed */
	spinlock_t lock;	/* guards read or write of above */
};

/*
 * Invalid partition error code
 */
enum prs_errcode {
	PERR_NONE = 0,
	PERR_INVCPUS,
	PERR_INVPARENT,
	PERR_NOTPART,
	PERR_NOTEXCL,
	PERR_NOCPUS,
	PERR_HOTPLUG,
	PERR_CPUSEMPTY,
	PERR_HKEEPING,
	PERR_ACCESS,
};

/* bits in struct cpuset flags field */
typedef enum {
	CS_ONLINE,
	CS_CPU_EXCLUSIVE,
	CS_MEM_EXCLUSIVE,
	CS_MEM_HARDWALL,
	CS_MEMORY_MIGRATE,
	CS_SCHED_LOAD_BALANCE,
	CS_SPREAD_PAGE,
	CS_SPREAD_SLAB,
} cpuset_flagbits_t;

/* The various types of files and directories in a cpuset file system */

typedef enum {
	FILE_MEMORY_MIGRATE,
	FILE_CPULIST,
	FILE_MEMLIST,
	FILE_EFFECTIVE_CPULIST,
	FILE_EFFECTIVE_MEMLIST,
	FILE_SUBPARTS_CPULIST,
	FILE_EXCLUSIVE_CPULIST,
	FILE_EFFECTIVE_XCPULIST,
	FILE_ISOLATED_CPULIST,
	FILE_CPU_EXCLUSIVE,
	FILE_MEM_EXCLUSIVE,
	FILE_MEM_HARDWALL,
	FILE_SCHED_LOAD_BALANCE,
	FILE_PARTITION_ROOT,
	FILE_SCHED_RELAX_DOMAIN_LEVEL,
	FILE_MEMORY_PRESSURE_ENABLED,
	FILE_MEMORY_PRESSURE,
	FILE_SPREAD_PAGE,
	FILE_SPREAD_SLAB,
} cpuset_filetype_t;

struct cpuset {
	struct cgroup_subsys_state css;

	unsigned long flags;		/* "unsigned long" so bitops work */

	/*
	 * On default hierarchy:
	 *
	 * The user-configured masks can only be changed by writing to
	 * cpuset.cpus and cpuset.mems, and won't be limited by the
	 * parent masks.
	 *
	 * The effective masks is the real masks that apply to the tasks
	 * in the cpuset. They may be changed if the configured masks are
	 * changed or hotplug happens.
	 *
	 * effective_mask == configured_mask & parent's effective_mask,
	 * and if it ends up empty, it will inherit the parent's mask.
	 *
	 *
	 * On legacy hierarchy:
	 *
	 * The user-configured masks are always the same with effective masks.
	 */

	/* user-configured CPUs and Memory Nodes allow to tasks */
	cpumask_var_t cpus_allowed;
	nodemask_t mems_allowed;

	/* effective CPUs and Memory Nodes allow to tasks */
	cpumask_var_t effective_cpus;
	nodemask_t effective_mems;

	/*
	 * Exclusive CPUs dedicated to current cgroup (default hierarchy only)
	 *
	 * The effective_cpus of a valid partition root comes solely from its
	 * effective_xcpus and some of the effective_xcpus may be distributed
	 * to sub-partitions below & hence excluded from its effective_cpus.
	 * For a valid partition root, its effective_cpus have no relationship
	 * with cpus_allowed unless its exclusive_cpus isn't set.
	 *
	 * This value will only be set if either exclusive_cpus is set or
	 * when this cpuset becomes a local partition root.
	 */
	cpumask_var_t effective_xcpus;

	/*
	 * Exclusive CPUs as requested by the user (default hierarchy only)
	 *
	 * Its value is independent of cpus_allowed and designates the set of
	 * CPUs that can be granted to the current cpuset or its children when
	 * it becomes a valid partition root. The effective set of exclusive
	 * CPUs granted (effective_xcpus) depends on whether those exclusive
	 * CPUs are passed down by its ancestors and not yet taken up by
	 * another sibling partition root along the way.
	 *
	 * If its value isn't set, it defaults to cpus_allowed.
	 */
	cpumask_var_t exclusive_cpus;

	/*
	 * This is old Memory Nodes tasks took on.
	 *
	 * - top_cpuset.old_mems_allowed is initialized to mems_allowed.
	 * - A new cpuset's old_mems_allowed is initialized when some
	 *   task is moved into it.
	 * - old_mems_allowed is used in cpuset_migrate_mm() when we change
	 *   cpuset.mems_allowed and have tasks' nodemask updated, and
	 *   then old_mems_allowed is updated to mems_allowed.
	 */
	nodemask_t old_mems_allowed;

	struct fmeter fmeter;		/* memory_pressure filter */

	/*
	 * Tasks are being attached to this cpuset.  Used to prevent
	 * zeroing cpus/mems_allowed between ->can_attach() and ->attach().
	 */
	int attach_in_progress;

	/* for custom sched domain */
	int relax_domain_level;

	/* number of valid local child partitions */
	int nr_subparts;

	/* partition root state */
	int partition_root_state;

	/*
	 * number of SCHED_DEADLINE tasks attached to this cpuset, so that we
	 * know when to rebuild associated root domain bandwidth information.
	 */
	int nr_deadline_tasks;
	int nr_migrate_dl_tasks;
	u64 sum_migrate_dl_bw;

	/* Invalid partition error code, not lock protected */
	enum prs_errcode prs_err;

	/* Handle for cpuset.cpus.partition */
	struct cgroup_file partition_file;

	/* Remote partition silbling list anchored at remote_children */
	struct list_head remote_sibling;

	/* Used to merge intersecting subsets for generate_sched_domains */
	struct uf_node node;
};

static inline struct cpuset *css_cs(struct cgroup_subsys_state *css)
{
	return css ? container_of(css, struct cpuset, css) : NULL;
}

/* Retrieve the cpuset for a task */
static inline struct cpuset *task_cs(struct task_struct *task)
{
	return css_cs(task_css(task, cpuset_cgrp_id));
}

static inline struct cpuset *parent_cs(struct cpuset *cs)
{
	return css_cs(cs->css.parent);
}

/* convenient tests for these bits */
static inline bool is_cpuset_online(struct cpuset *cs)
{
	return test_bit(CS_ONLINE, &cs->flags) && !css_is_dying(&cs->css);
}

static inline int is_cpu_exclusive(const struct cpuset *cs)
{
	return test_bit(CS_CPU_EXCLUSIVE, &cs->flags);
}

static inline int is_mem_exclusive(const struct cpuset *cs)
{
	return test_bit(CS_MEM_EXCLUSIVE, &cs->flags);
}

static inline int is_mem_hardwall(const struct cpuset *cs)
{
	return test_bit(CS_MEM_HARDWALL, &cs->flags);
}

static inline int is_sched_load_balance(const struct cpuset *cs)
{
	return test_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
}

static inline int is_memory_migrate(const struct cpuset *cs)
{
	return test_bit(CS_MEMORY_MIGRATE, &cs->flags);
}

static inline int is_spread_page(const struct cpuset *cs)
{
	return test_bit(CS_SPREAD_PAGE, &cs->flags);
}

static inline int is_spread_slab(const struct cpuset *cs)
{
	return test_bit(CS_SPREAD_SLAB, &cs->flags);
}

void rebuild_sched_domains_locked(void);

/*
 * cpuset-v1.c
 */
void fmeter_init(struct fmeter *fmp);
int fmeter_getrate(struct fmeter *fmp);
int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
			    s64 val);
s64 cpuset_read_s64(struct cgroup_subsys_state *css, struct cftype *cft);
void cpuset_update_task_spread_flags(struct cpuset *cs,
					struct task_struct *tsk);
void update_tasks_flags(struct cpuset *cs);

#endif /* __CPUSET_INTERNAL_H */