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- /* SPDX-License-Identifier: GPL-2.0 */
- #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/sched/topology.h>
- #include <linux/sched/task.h>
- #include <linux/cpumask.h>
- #include <linux/nodemask.h>
- #include <linux/mm.h>
- #include <linux/mmu_context.h>
- #include <linux/jump_label.h>
- #ifdef CONFIG_CPUSETS
- /*
- * Static branch rewrites can happen in an arbitrary order for a given
- * key. In code paths where we need to loop with read_mems_allowed_begin() and
- * read_mems_allowed_retry() to get a consistent view of mems_allowed, we need
- * to ensure that begin() always gets rewritten before retry() in the
- * disabled -> enabled transition. If not, then if local irqs are disabled
- * around the loop, we can deadlock since retry() would always be
- * comparing the latest value of the mems_allowed seqcount against 0 as
- * begin() still would see cpusets_enabled() as false. The enabled -> disabled
- * transition should happen in reverse order for the same reasons (want to stop
- * looking at real value of mems_allowed.sequence in retry() first).
- */
- extern struct static_key_false cpusets_pre_enable_key;
- extern struct static_key_false cpusets_enabled_key;
- extern struct static_key_false cpusets_insane_config_key;
- static inline bool cpusets_enabled(void)
- {
- return static_branch_unlikely(&cpusets_enabled_key);
- }
- static inline void cpuset_inc(void)
- {
- static_branch_inc_cpuslocked(&cpusets_pre_enable_key);
- static_branch_inc_cpuslocked(&cpusets_enabled_key);
- }
- static inline void cpuset_dec(void)
- {
- static_branch_dec_cpuslocked(&cpusets_enabled_key);
- static_branch_dec_cpuslocked(&cpusets_pre_enable_key);
- }
- /*
- * This will get enabled whenever a cpuset configuration is considered
- * unsupportable in general. E.g. movable only node which cannot satisfy
- * any non movable allocations (see update_nodemask). Page allocator
- * needs to make additional checks for those configurations and this
- * check is meant to guard those checks without any overhead for sane
- * configurations.
- */
- static inline bool cpusets_insane_config(void)
- {
- return static_branch_unlikely(&cpusets_insane_config_key);
- }
- extern int cpuset_init(void);
- extern void cpuset_init_smp(void);
- extern void cpuset_force_rebuild(void);
- extern void cpuset_update_active_cpus(void);
- extern void cpuset_wait_for_hotplug(void);
- extern void inc_dl_tasks_cs(struct task_struct *task);
- extern void dec_dl_tasks_cs(struct task_struct *task);
- extern void cpuset_lock(void);
- extern void cpuset_unlock(void);
- extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask);
- extern bool 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 bool __cpuset_node_allowed(int node, gfp_t gfp_mask);
- static inline bool cpuset_node_allowed(int node, gfp_t gfp_mask)
- {
- if (cpusets_enabled())
- return __cpuset_node_allowed(node, gfp_mask);
- return true;
- }
- static inline bool __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
- {
- return __cpuset_node_allowed(zone_to_nid(z), gfp_mask);
- }
- static inline bool cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
- {
- if (cpusets_enabled())
- return __cpuset_zone_allowed(z, gfp_mask);
- return true;
- }
- 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 void cpuset_task_status_allowed(struct seq_file *m,
- struct task_struct *task);
- extern int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns,
- struct pid *pid, struct task_struct *tsk);
- extern int cpuset_mem_spread_node(void);
- extern int cpuset_slab_spread_node(void);
- static inline int cpuset_do_page_mem_spread(void)
- {
- return task_spread_page(current);
- }
- static inline int cpuset_do_slab_mem_spread(void)
- {
- return task_spread_slab(current);
- }
- extern bool current_cpuset_is_being_rebound(void);
- extern void rebuild_sched_domains(void);
- extern void cpuset_print_current_mems_allowed(void);
- /*
- * read_mems_allowed_begin 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 read_mems_allowed_begin and
- * read_mems_allowed_retry prevents these artificial failures.
- */
- static inline unsigned int read_mems_allowed_begin(void)
- {
- if (!static_branch_unlikely(&cpusets_pre_enable_key))
- return 0;
- return read_seqcount_begin(¤t->mems_allowed_seq);
- }
- /*
- * If this returns true, the operation that took place after
- * read_mems_allowed_begin may have failed artificially due to a concurrent
- * update of mems_allowed. It is up to the caller to retry the operation if
- * appropriate.
- */
- static inline bool read_mems_allowed_retry(unsigned int seq)
- {
- if (!static_branch_unlikely(&cpusets_enabled_key))
- return false;
- return read_seqcount_retry(¤t->mems_allowed_seq, seq);
- }
- static inline void set_mems_allowed(nodemask_t nodemask)
- {
- unsigned long flags;
- task_lock(current);
- local_irq_save(flags);
- write_seqcount_begin(¤t->mems_allowed_seq);
- current->mems_allowed = nodemask;
- write_seqcount_end(¤t->mems_allowed_seq);
- local_irq_restore(flags);
- task_unlock(current);
- }
- #else /* !CONFIG_CPUSETS */
- static inline bool cpusets_enabled(void) { return false; }
- static inline bool cpusets_insane_config(void) { return false; }
- static inline int cpuset_init(void) { return 0; }
- static inline void cpuset_init_smp(void) {}
- static inline void cpuset_force_rebuild(void) { }
- static inline void cpuset_update_active_cpus(void)
- {
- partition_sched_domains(1, NULL, NULL);
- }
- static inline void cpuset_wait_for_hotplug(void) { }
- static inline void inc_dl_tasks_cs(struct task_struct *task) { }
- static inline void dec_dl_tasks_cs(struct task_struct *task) { }
- static inline void cpuset_lock(void) { }
- static inline void cpuset_unlock(void) { }
- static inline void cpuset_cpus_allowed(struct task_struct *p,
- struct cpumask *mask)
- {
- cpumask_copy(mask, task_cpu_possible_mask(p));
- }
- static inline bool cpuset_cpus_allowed_fallback(struct task_struct *p)
- {
- return false;
- }
- static inline nodemask_t cpuset_mems_allowed(struct task_struct *p)
- {
- return node_possible_map;
- }
- #define cpuset_current_mems_allowed (node_states[N_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 bool cpuset_node_allowed(int node, gfp_t gfp_mask)
- {
- return true;
- }
- static inline bool __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
- {
- return true;
- }
- static inline bool cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
- {
- return true;
- }
- 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 bool current_cpuset_is_being_rebound(void)
- {
- return false;
- }
- static inline void rebuild_sched_domains(void)
- {
- partition_sched_domains(1, NULL, NULL);
- }
- static inline void cpuset_print_current_mems_allowed(void)
- {
- }
- static inline void set_mems_allowed(nodemask_t nodemask)
- {
- }
- static inline unsigned int read_mems_allowed_begin(void)
- {
- return 0;
- }
- static inline bool read_mems_allowed_retry(unsigned int seq)
- {
- return false;
- }
- #endif /* !CONFIG_CPUSETS */
- #endif /* _LINUX_CPUSET_H */
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