Bjoern's Dissertation Code with Priority Donationwip-splitting-omlp-jerickso

1 files changed, 292 insertions, 0 deletions

diff --git a/include/litmus/litmus.h b/include/litmus/litmus.h
new file mode 100644
index 000000000000..31ac72eddef7
--- /dev/null
+++ b/include/litmus/litmus.h
@@ -0,0 +1,292 @@
+/*
+ * Constant definitions related to
+ * scheduling policy.
+ */
+
+#ifndef _LINUX_LITMUS_H_
+#define _LINUX_LITMUS_H_
+
+#include <litmus/debug_trace.h>
+
+#ifdef CONFIG_RELEASE_MASTER
+extern atomic_t release_master_cpu;
+#endif
+
+/* in_list - is a given list_head queued on some list?
+ */
+static inline int in_list(struct list_head* list)
+{
+        return !(  /* case 1: deleted */
+                   (list->next == LIST_POISON1 &&
+                    list->prev == LIST_POISON2)
+                 ||
+                   /* case 2: initialized */
+                   (list->next == list &&
+                    list->prev == list)
+                );
+}
+
+#define NO_CPU                  0xffffffff
+
+void litmus_fork(struct task_struct *tsk);
+void litmus_exec(void);
+/* clean up real-time state of a task */
+void exit_litmus(struct task_struct *dead_tsk);
+
+long litmus_admit_task(struct task_struct *tsk);
+void litmus_exit_task(struct task_struct *tsk);
+
+#define is_realtime(t)          ((t)->policy == SCHED_LITMUS)
+#define rt_transition_pending(t) \
+        ((t)->rt_param.transition_pending)
+
+#define tsk_rt(t)               (&(t)->rt_param)
+
+/*      Realtime utility macros */
+#define get_rt_flags(t)         (tsk_rt(t)->flags)
+#define set_rt_flags(t,f)       (tsk_rt(t)->flags=(f))
+#define get_exec_cost(t)        (tsk_rt(t)->task_params.exec_cost)
+#define get_exec_time(t)        (tsk_rt(t)->job_params.exec_time)
+#define get_rt_period(t)        (tsk_rt(t)->task_params.period)
+#define get_rt_phase(t)         (tsk_rt(t)->task_params.phase)
+#define get_partition(t)        (tsk_rt(t)->task_params.cpu)
+#define get_priority(t)         (tsk_rt(t)->task_params.priority)
+#define get_deadline(t)         (tsk_rt(t)->job_params.deadline)
+#define get_release(t)          (tsk_rt(t)->job_params.release)
+#define get_class(t)            (tsk_rt(t)->task_params.cls)
+
+#define is_priority_boosted(t)  (tsk_rt(t)->priority_boosted)
+#define get_boost_start(t)      (tsk_rt(t)->boost_start_time)
+
+inline static int budget_exhausted(struct task_struct* t)
+{
+        return get_exec_time(t) >= get_exec_cost(t);
+}
+
+inline static lt_t budget_remaining(struct task_struct* t)
+{
+        if (!budget_exhausted(t))
+                return get_exec_cost(t) - get_exec_time(t);
+        else
+                /* avoid overflow */
+                return 0;
+}
+
+#define budget_enforced(t) (tsk_rt(t)->task_params.budget_policy != NO_ENFORCEMENT)
+
+#define budget_precisely_enforced(t) (tsk_rt(t)->task_params.budget_policy \
+                                      == PRECISE_ENFORCEMENT)
+
+#define is_hrt(t)               \
+        (tsk_rt(t)->task_params.cls == RT_CLASS_HARD)
+#define is_srt(t)               \
+        (tsk_rt(t)->task_params.cls == RT_CLASS_SOFT)
+#define is_be(t)                \
+        (tsk_rt(t)->task_params.cls == RT_CLASS_BEST_EFFORT)
+
+/* Our notion of time within LITMUS: kernel monotonic time. */
+static inline lt_t litmus_clock(void)
+{
+        return ktime_to_ns(ktime_get());
+}
+
+/* A macro to convert from nanoseconds to ktime_t. */
+#define ns_to_ktime(t)          ktime_add_ns(ktime_set(0, 0), t)
+
+#define get_domain(t) (tsk_rt(t)->domain)
+
+/* Honor the flag in the preempt_count variable that is set
+ * when scheduling is in progress.
+ */
+#define is_running(t)                   \
+        ((t)->state == TASK_RUNNING ||  \
+         task_thread_info(t)->preempt_count & PREEMPT_ACTIVE)
+
+#define is_blocked(t)       \
+        (!is_running(t))
+#define is_released(t, now)     \
+        (lt_before_eq(get_release(t), now))
+#define is_tardy(t, now)    \
+        (lt_before_eq(tsk_rt(t)->job_params.deadline, now))
+
+/* real-time comparison macros */
+#define earlier_deadline(a, b) (lt_before(\
+        (a)->rt_param.job_params.deadline,\
+        (b)->rt_param.job_params.deadline))
+#define earlier_release(a, b)  (lt_before(\
+        (a)->rt_param.job_params.release,\
+        (b)->rt_param.job_params.release))
+
+void preempt_if_preemptable(struct task_struct* t, int on_cpu);
+
+#ifdef CONFIG_LITMUS_LOCKING
+void srp_ceiling_block(void);
+#else
+#define srp_ceiling_block() /* nothing */
+#endif
+
+#define bheap2task(hn) ((struct task_struct*) hn->value)
+
+static inline struct control_page* get_control_page(struct task_struct *t)
+{
+        return tsk_rt(t)->ctrl_page;
+}
+
+static inline int has_control_page(struct task_struct* t)
+{
+        return tsk_rt(t)->ctrl_page != NULL;
+}
+
+#ifdef CONFIG_NP_SECTION
+
+static inline int is_kernel_np(struct task_struct *t)
+{
+        return tsk_rt(t)->kernel_np;
+}
+
+static inline int is_user_np(struct task_struct *t)
+{
+        return tsk_rt(t)->ctrl_page ? tsk_rt(t)->ctrl_page->sched.np.flag : 0;
+}
+
+static inline void request_exit_np(struct task_struct *t)
+{
+        if (is_user_np(t)) {
+                /* Set the flag that tells user space to call
+                 * into the kernel at the end of a critical section. */
+                if (likely(tsk_rt(t)->ctrl_page)) {
+                        TRACE_TASK(t, "setting delayed_preemption flag\n");
+                        tsk_rt(t)->ctrl_page->sched.np.preempt = 1;
+                }
+        }
+}
+
+static inline void make_np(struct task_struct *t)
+{
+        tsk_rt(t)->kernel_np++;
+}
+
+/* Caller should check if preemption is necessary when
+ * the function return 0.
+ */
+static inline int take_np(struct task_struct *t)
+{
+        return --tsk_rt(t)->kernel_np;
+}
+
+/* returns 0 if remote CPU needs an IPI to preempt, 1 if no IPI is required */
+static inline int request_exit_np_atomic(struct task_struct *t)
+{
+        union np_flag old, new;
+        int ok;
+
+        if (tsk_rt(t)->ctrl_page) {
+                old.raw = tsk_rt(t)->ctrl_page->sched.raw;
+                if (old.np.flag == 0) {
+                        /* no longer non-preemptive */
+                        return 0;
+                } else if (old.np.preempt) {
+                        /* already set, nothing for us to do */
+                        TRACE_TASK(t, "not setting np.preempt flag again\n");
+                        return 1;
+                } else {
+                        /* non preemptive and flag not set */
+                        new.raw = old.raw;
+                        new.np.preempt = 1;
+                        /* if we get old back, then we atomically set the flag */
+                        ok = cmpxchg(&tsk_rt(t)->ctrl_page->sched.raw, old.raw, new.raw) == old.raw;
+                        /* If we raced with a concurrent change, then so be
+                         * it. Deliver it by IPI.  We don't want an unbounded
+                         * retry loop here since tasks might exploit that to
+                         * keep the kernel busy indefinitely. */
+                        TRACE_TASK(t,  "request_exit_np => %d\n", ok);
+                        return ok;
+                }
+        } else
+                return 0;
+}
+
+#else
+
+static inline int is_kernel_np(struct task_struct* t)
+{
+        return 0;
+}
+
+static inline int is_user_np(struct task_struct* t)
+{
+        return 0;
+}
+
+static inline void request_exit_np(struct task_struct *t)
+{
+        /* request_exit_np() shouldn't be called if !CONFIG_NP_SECTION */
+        BUG();
+}
+
+static inline int request_exist_np_atomic(struct task_struct *t)
+{
+        return 0;
+}
+
+#endif
+
+static inline void clear_exit_np(struct task_struct *t)
+{
+        if (likely(tsk_rt(t)->ctrl_page))
+                tsk_rt(t)->ctrl_page->sched.np.preempt = 0;
+}
+
+static inline int is_np(struct task_struct *t)
+{
+#ifdef CONFIG_SCHED_DEBUG_TRACE
+        int kernel, user;
+        kernel = is_kernel_np(t);
+        user   = is_user_np(t);
+        if (kernel || user)
+                TRACE_TASK(t, " is non-preemptive: kernel=%d user=%d\n",
+
+                           kernel, user);
+        return kernel || user;
+#else
+        return unlikely(is_kernel_np(t) || is_user_np(t));
+#endif
+}
+
+static inline int is_present(struct task_struct* t)
+{
+        return t && tsk_rt(t)->present;
+}
+
+
+/* make the unit explicit */
+typedef unsigned long quanta_t;
+
+enum round {
+        FLOOR,
+        CEIL
+};
+
+
+/* Tick period is used to convert ns-specified execution
+ * costs and periods into tick-based equivalents.
+ */
+extern ktime_t tick_period;
+
+static inline quanta_t time2quanta(lt_t time, enum round round)
+{
+        s64  quantum_length = ktime_to_ns(tick_period);
+
+        if (do_div(time, quantum_length) && round == CEIL)
+                time++;
+        return (quanta_t) time;
+}
+
+/* By how much is cpu staggered behind CPU 0? */
+u64 cpu_stagger_offset(int cpu);
+
+#define TS_SYSCALL_IN_START                                             \
+        if (has_control_page(current))                                  \
+                __TS_SYSCALL_IN_START(&get_control_page(current)->ts_syscall_start);
+
+#endif