MC2 scheduler and partition modules

1 files changed, 256 insertions, 0 deletions

diff --git a/include/litmus/reservation.h b/include/litmus/reservation.h
new file mode 100644
index 000000000000..7e022b34470f
--- /dev/null
+++ b/include/litmus/reservation.h
@@ -0,0 +1,256 @@
+#ifndef LITMUS_RESERVATION_H
+#define LITMUS_RESERVATION_H
+
+#include <linux/list.h>
+#include <linux/hrtimer.h>
+
+struct reservation_client;
+struct reservation_environment;
+struct reservation;
+
+typedef enum {
+        /* reservation has no clients, is not consuming budget */
+        RESERVATION_INACTIVE = 0,
+
+        /* reservation has clients, consumes budget when scheduled */
+        RESERVATION_ACTIVE,
+
+        /* reservation has no clients, but may be consuming budget */
+        RESERVATION_ACTIVE_IDLE,
+
+        /* Reservation has no budget and waits for
+         * replenishment. May or may not have clients. */
+        RESERVATION_DEPLETED,
+} reservation_state_t;
+
+
+/* ************************************************************************** */
+
+/* Select which task to dispatch. If NULL is returned, it means there is nothing
+ * to schedule right now and background work can be scheduled. */
+typedef struct task_struct * (*dispatch_t)  (
+        struct reservation_client *client
+);
+
+/* Something that can be managed in a reservation and that can yield
+ * a process for dispatching. Contains a pointer to the reservation
+ * to which it "belongs". */
+struct reservation_client {
+        struct list_head list;
+        struct reservation* reservation;
+        dispatch_t dispatch;
+};
+
+
+/* ************************************************************************** */
+
+/* Called by reservations to request state change. */
+typedef void (*reservation_change_state_t)  (
+        struct reservation_environment* env,
+        struct reservation *res,
+        reservation_state_t new_state
+);
+
+/* The framework within wich reservations operate. */
+struct reservation_environment {
+        lt_t time_zero;
+        lt_t current_time;
+
+        /* services invoked by reservations */
+        reservation_change_state_t change_state;
+};
+
+
+/* ************************************************************************** */
+
+/* A new client is added or an existing client resumes. */
+typedef void (*client_arrives_t)  (
+        struct reservation *reservation,
+        struct reservation_client *client
+);
+
+/* A client suspends or terminates. */
+typedef void (*client_departs_t)  (
+        struct reservation *reservation,
+        struct reservation_client *client,
+        int did_signal_job_completion
+);
+
+/* A previously requested replenishment has occurred. */
+typedef void (*on_replenishment_timer_t)  (
+        struct reservation *reservation
+);
+
+/* Update the reservation's budget to reflect execution or idling. */
+typedef void (*drain_budget_t) (
+        struct reservation *reservation,
+        lt_t how_much
+);
+
+/* Select a ready task from one of the clients for scheduling. */
+typedef struct task_struct* (*dispatch_client_t)  (
+        struct reservation *reservation,
+        lt_t *time_slice /* May be used to force rescheduling after
+                            some amount of time. 0 => no limit */
+);
+
+
+struct reservation_ops {
+        dispatch_client_t dispatch_client;
+
+        client_arrives_t client_arrives;
+        client_departs_t client_departs;
+
+        on_replenishment_timer_t replenish;
+        drain_budget_t drain_budget;
+};
+
+struct reservation {
+        /* used to queue in environment */
+        struct list_head list;
+
+        reservation_state_t state;
+        unsigned int id;
+
+        /* exact meaning defined by impl. */
+        lt_t priority;
+        lt_t cur_budget;
+        lt_t next_replenishment;
+
+        /* budget stats */
+        lt_t budget_consumed; /* how much budget consumed in this allocation cycle? */
+        lt_t budget_consumed_total;
+
+        /* interaction with framework */
+        struct reservation_environment *env;
+        struct reservation_ops *ops;
+
+        struct list_head clients;
+        
+        /* for global env. */
+        int scheduled_on;
+        int event_added;
+        /* for blocked by ghost. Do not charge budget when ACTIVE */
+        int blocked_by_ghost;
+        /* ghost_job. If it is clear, do not charge budget when ACTIVE_IDLE */
+        int is_ghost;
+};
+
+void reservation_init(struct reservation *res);
+
+/* Default implementations */
+
+/* simply select the first client in the list, set *for_at_most to zero */
+struct task_struct* default_dispatch_client(
+        struct reservation *res,
+        lt_t *for_at_most
+);
+
+/* "connector" reservation client to hook up tasks with reservations */
+struct task_client {
+        struct reservation_client client;
+        struct task_struct *task;
+};
+
+void task_client_init(struct task_client *tc, struct task_struct *task,
+        struct reservation *reservation);
+
+#define SUP_RESCHEDULE_NOW (0)
+#define SUP_NO_SCHEDULER_UPDATE (ULLONG_MAX)
+
+/* A simple uniprocessor (SUP) flat (i.e., non-hierarchical) reservation
+ * environment.
+ */
+struct sup_reservation_environment {
+        struct reservation_environment env;
+
+        /* ordered by priority */
+        struct list_head active_reservations;
+
+        /* ordered by next_replenishment */
+        struct list_head depleted_reservations;
+
+        /* unordered */
+        struct list_head inactive_reservations;
+
+        /* - SUP_RESCHEDULE_NOW means call sup_dispatch() now
+         * - SUP_NO_SCHEDULER_UPDATE means nothing to do
+         * any other value means program a timer for the given time
+         */
+        lt_t next_scheduler_update;
+        /* set to true if a call to sup_dispatch() is imminent */
+        bool will_schedule;
+};
+
+/* Contract:
+ *  - before calling into sup_ code, or any reservation methods,
+ *    update the time with sup_update_time(); and
+ *  - after calling into sup_ code, or any reservation methods,
+ *    check next_scheduler_update and program timer or trigger
+ *    scheduler invocation accordingly.
+ */
+
+void sup_init(struct sup_reservation_environment* sup_env);
+void sup_add_new_reservation(struct sup_reservation_environment* sup_env,
+        struct reservation* new_res);
+void sup_scheduler_update_after(struct sup_reservation_environment* sup_env,
+        lt_t timeout);
+void sup_update_time(struct sup_reservation_environment* sup_env, lt_t now);
+struct task_struct* sup_dispatch(struct sup_reservation_environment* sup_env);
+
+struct reservation* sup_find_by_id(struct sup_reservation_environment* sup_env,
+        unsigned int id);
+        
+/* A global multiprocessor reservation environment. */
+
+typedef enum {
+        EVENT_REPLENISH = 0,
+        EVENT_DRAIN,
+        EVENT_OTHERS,
+} event_type_t;
+
+
+struct next_timer_event {
+        lt_t next_update;
+        int timer_armed_on;
+        unsigned int id;
+        event_type_t type;
+        struct list_head list;
+};
+
+struct gmp_reservation_environment {
+        raw_spinlock_t lock;
+        struct reservation_environment env;
+
+        /* ordered by priority */
+        struct list_head active_reservations;
+
+        /* ordered by next_replenishment */
+        struct list_head depleted_reservations;
+
+        /* unordered */
+        struct list_head inactive_reservations;
+
+        /* timer event ordered by next_update */
+        struct list_head next_events;
+        
+        /* (schedule_now == true) means call gmp_dispatch() now */
+        int schedule_now;
+        /* set to true if a call to gmp_dispatch() is imminent */
+        bool will_schedule;
+};
+
+void gmp_init(struct gmp_reservation_environment* gmp_env);
+void gmp_add_new_reservation(struct gmp_reservation_environment* gmp_env,
+        struct reservation* new_res);
+void gmp_add_event_after(struct gmp_reservation_environment* gmp_env,
+        lt_t timeout, unsigned int id, event_type_t type);
+void gmp_print_events(struct gmp_reservation_environment* gmp_env, lt_t now);
+int gmp_update_time(struct gmp_reservation_environment* gmp_env, lt_t now);
+struct task_struct* gmp_dispatch(struct gmp_reservation_environment* gmp_env);
+struct next_timer_event* gmp_find_event_by_id(struct gmp_reservation_environment* gmp_env, unsigned int id);
+struct next_timer_event* gmp_find_event_by_time(struct gmp_reservation_environment* gmp_env, lt_t when);
+struct reservation* gmp_find_by_id(struct gmp_reservation_environment* gmp_env,
+        unsigned int id);
+
+#endif