1 files changed, 308 insertions, 0 deletions
diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h
new file mode 100644
index 000000000..0348dba56
--- /dev/null
+++ b/include/linux/cpuset.h
@@ -0,0 +1,308 @@
+/* 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(&current->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(&current->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(&current->mems_allowed_seq);
+	current->mems_allowed = nodemask;
+	write_seqcount_end(&current->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 */