| /* 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 cpuset_read_lock(void); |
| extern void cpuset_read_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 cpuset_read_lock(void) { } |
| static inline void cpuset_read_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 */ |