cpuset.h

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#ifndef _LINUX_CPUSET_H
#define _LINUX_CPUSET_H
/*
 *  cpuset interface
 *
 *  Copyright (C) 2003 BULL SA
 *  Copyright (C) 2004-2006 Silicon Graphics, Inc.
 *
 */

#include <linux/sched.h>
#include <linux/cpumask.h>
#include <linux/nodemask.h>
#include <linux/cgroup.h>
#include <linux/mm.h>

#ifdef CONFIG_CPUSETS

extern int number_of_cpusets;   /* How many cpusets are defined in system? */

extern int cpuset_init(void);
extern void cpuset_init_smp(void);
extern void cpuset_update_active_cpus(bool cpu_online);
extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask);
extern void cpuset_cpus_allowed_fallback(struct task_struct *p);
extern nodemask_t cpuset_mems_allowed(struct task_struct *p);
#define cpuset_current_mems_allowed (current->mems_allowed)
void cpuset_init_current_mems_allowed(void);
int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask);

extern int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask);
extern int __cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask);

static inline int cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
{
    return number_of_cpusets <= 1 ||
        __cpuset_node_allowed_softwall(node, gfp_mask);
}

static inline int cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask)
{
    return number_of_cpusets <= 1 ||
        __cpuset_node_allowed_hardwall(node, gfp_mask);
}

static inline int cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask)
{
    return cpuset_node_allowed_softwall(zone_to_nid(z), gfp_mask);
}

static inline int cpuset_zone_allowed_hardwall(struct zone *z, gfp_t gfp_mask)
{
    return cpuset_node_allowed_hardwall(zone_to_nid(z), gfp_mask);
}

extern int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
                      const struct task_struct *tsk2);

#define cpuset_memory_pressure_bump()               \
    do {                            \
        if (cpuset_memory_pressure_enabled)     \
            __cpuset_memory_pressure_bump();    \
    } while (0)
extern int cpuset_memory_pressure_enabled;
extern void __cpuset_memory_pressure_bump(void);

extern const struct file_operations proc_cpuset_operations;
struct seq_file;
extern void cpuset_task_status_allowed(struct seq_file *m,
                    struct task_struct *task);

extern int cpuset_mem_spread_node(void);
extern int cpuset_slab_spread_node(void);

static inline int cpuset_do_page_mem_spread(void)
{
    return current->flags & PF_SPREAD_PAGE;
}

static inline int cpuset_do_slab_mem_spread(void)
{
    return current->flags & PF_SPREAD_SLAB;
}

extern int current_cpuset_is_being_rebound(void);

extern void rebuild_sched_domains(void);

extern void cpuset_print_task_mems_allowed(struct task_struct *p);

/*
 * get_mems_allowed is required when making decisions involving mems_allowed
 * such as during page allocation. mems_allowed can be updated in parallel
 * and depending on the new value an operation can fail potentially causing
 * process failure. A retry loop with get_mems_allowed and put_mems_allowed
 * prevents these artificial failures.
 */
static inline unsigned int get_mems_allowed(void)
{
    return read_seqcount_begin(&current->mems_allowed_seq);
}

/*
 * If this returns false, the operation that took place after get_mems_allowed
 * may have failed. It is up to the caller to retry the operation if
 * appropriate.
 */
static inline bool put_mems_allowed(unsigned int seq)
{
    return !read_seqcount_retry(&current->mems_allowed_seq, seq);
}

static inline void set_mems_allowed(nodemask_t nodemask)
{
    task_lock(current);
    write_seqcount_begin(&current->mems_allowed_seq);
    current->mems_allowed = nodemask;
    write_seqcount_end(&current->mems_allowed_seq);
    task_unlock(current);
}

#else /* !CONFIG_CPUSETS */

static inline int cpuset_init(void) { return 0; }
static inline void cpuset_init_smp(void) {}

static inline void cpuset_update_active_cpus(bool cpu_online)
{
    partition_sched_domains(1, NULL, NULL);
}

static inline void cpuset_cpus_allowed(struct task_struct *p,
                       struct cpumask *mask)
{
    cpumask_copy(mask, cpu_possible_mask);
}

static inline void cpuset_cpus_allowed_fallback(struct task_struct *p)
{
}

static inline nodemask_t cpuset_mems_allowed(struct task_struct *p)
{
    return node_possible_map;
}

#define cpuset_current_mems_allowed (node_states[N_HIGH_MEMORY])
static inline void cpuset_init_current_mems_allowed(void) {}

static inline int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask)
{
    return 1;
}

static inline int cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
{
    return 1;
}

static inline int cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask)
{
    return 1;
}

static inline int cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask)
{
    return 1;
}

static inline int cpuset_zone_allowed_hardwall(struct zone *z, gfp_t gfp_mask)
{
    return 1;
}

static inline int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
                         const struct task_struct *tsk2)
{
    return 1;
}

static inline void cpuset_memory_pressure_bump(void) {}

static inline void cpuset_task_status_allowed(struct seq_file *m,
                        struct task_struct *task)
{
}

static inline int cpuset_mem_spread_node(void)
{
    return 0;
}

static inline int cpuset_slab_spread_node(void)
{
    return 0;
}

static inline int cpuset_do_page_mem_spread(void)
{
    return 0;
}

static inline int cpuset_do_slab_mem_spread(void)
{
    return 0;
}

static inline int current_cpuset_is_being_rebound(void)
{
    return 0;
}

static inline void rebuild_sched_domains(void)
{
    partition_sched_domains(1, NULL, NULL);
}

static inline void cpuset_print_task_mems_allowed(struct task_struct *p)
{
}

static inline void set_mems_allowed(nodemask_t nodemask)
{
}

static inline unsigned int get_mems_allowed(void)
{
    return 0;
}

static inline bool put_mems_allowed(unsigned int seq)
{
    return true;
}

#endif /* !CONFIG_CPUSETS */

#endif /* _LINUX_CPUSET_H */