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

31 files changed, 2202 insertions, 12 deletions

diff --git a/include/linux/completion.h b/include/linux/completion.h
index 51e3145196f6..c63950e8a863 100644
--- a/include/linux/completion.h
+++ b/include/linux/completion.h
@@ -90,6 +90,7 @@ extern bool completion_done(struct completion *x);
 
 extern void complete(struct completion *);
 extern void complete_all(struct completion *);
+extern void complete_n(struct completion *, int n);
 
 /**
  * INIT_COMPLETION: - reinitialize a completion structure
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 63d069bd80b7..29a672458d27 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -16,8 +16,8 @@
  * nr_file rlimit, so it's safe to set up a ridiculously high absolute
  * upper limit on files-per-process.
  *
- * Some programs (notably those using select()) may have to be 
- * recompiled to take full advantage of the new limits..  
+ * Some programs (notably those using select()) may have to be
+ * recompiled to take full advantage of the new limits..
  */
 
 /* Fixed constants first: */
@@ -172,7 +172,7 @@ struct inodes_stat_t {
 #define SEL_EX          4
 
 /* public flags for file_system_type */
-#define FS_REQUIRES_DEV 1 
+#define FS_REQUIRES_DEV 1
 #define FS_BINARY_MOUNTDATA 2
 #define FS_HAS_SUBTYPE 4
 #define FS_REVAL_DOT    16384   /* Check the paths ".", ".." for staleness */
@@ -470,7 +470,7 @@ struct iattr {
  */
 #include <linux/quota.h>
 
-/** 
+/**
  * enum positive_aop_returns - aop return codes with specific semantics
  *
  * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has
@@ -480,7 +480,7 @@ struct iattr {
  *                          be a candidate for writeback again in the near
  *                          future.  Other callers must be careful to unlock
  *                          the page if they get this return.  Returned by
- *                          writepage(); 
+ *                          writepage();
  *
  * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has
  *                      unlocked it and the page might have been truncated.
@@ -721,6 +721,7 @@ static inline int mapping_writably_mapped(struct address_space *mapping)
 
 struct posix_acl;
 #define ACL_NOT_CACHED ((void *)(-1))
+struct inode_obj_id_table;
 
 struct inode {
         struct hlist_node       i_hash;
@@ -784,6 +785,8 @@ struct inode {
         struct posix_acl        *i_acl;
         struct posix_acl        *i_default_acl;
 #endif
+        struct list_head        i_obj_list;
+        struct mutex            i_obj_mutex;
         void                    *i_private; /* fs or device private pointer */
 };
 
@@ -997,10 +1000,10 @@ static inline int file_check_writeable(struct file *filp)
 
 #define MAX_NON_LFS     ((1UL<<31) - 1)
 
-/* Page cache limit. The filesystems should put that into their s_maxbytes 
-   limits, otherwise bad things can happen in VM. */ 
+/* Page cache limit. The filesystems should put that into their s_maxbytes
+   limits, otherwise bad things can happen in VM. */
 #if BITS_PER_LONG==32
-#define MAX_LFS_FILESIZE        (((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1) 
+#define MAX_LFS_FILESIZE        (((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1)
 #elif BITS_PER_LONG==64
 #define MAX_LFS_FILESIZE        0x7fffffffffffffffUL
 #endif
@@ -2145,7 +2148,7 @@ extern int may_open(struct path *, int, int);
 
 extern int kernel_read(struct file *, loff_t, char *, unsigned long);
 extern struct file * open_exec(const char *);
- 
+
 /* fs/dcache.c -- generic fs support functions */
 extern int is_subdir(struct dentry *, struct dentry *);
 extern int path_is_under(struct path *, struct path *);
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index fd0c1b857d3d..76da541c1f66 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -167,6 +167,7 @@ struct hrtimer_clock_base {
  * @nr_retries:         Total number of hrtimer interrupt retries
  * @nr_hangs:           Total number of hrtimer interrupt hangs
  * @max_hang_time:      Maximum time spent in hrtimer_interrupt
+ * @to_pull:            LITMUS^RT list of timers to be pulled on this cpu
  */
 struct hrtimer_cpu_base {
         raw_spinlock_t                  lock;
@@ -180,8 +181,32 @@ struct hrtimer_cpu_base {
         unsigned long                   nr_hangs;
         ktime_t                         max_hang_time;
 #endif
+        struct list_head                to_pull;
 };
 
+#ifdef CONFIG_ARCH_HAS_SEND_PULL_TIMERS
+
+#define HRTIMER_START_ON_INACTIVE       0
+#define HRTIMER_START_ON_QUEUED         1
+
+/*
+ * struct hrtimer_start_on_info - save timer info on remote cpu
+ * @list:       list of hrtimer_start_on_info on remote cpu (to_pull)
+ * @timer:      timer to be triggered on remote cpu
+ * @time:       time event
+ * @mode:       timer mode
+ * @state:      activity flag
+ */
+struct hrtimer_start_on_info {
+        struct list_head        list;
+        struct hrtimer          *timer;
+        ktime_t                 time;
+        enum hrtimer_mode       mode;
+        atomic_t                state;
+};
+
+#endif
+
 static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time)
 {
         timer->_expires = time;
@@ -348,6 +373,13 @@ __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
                          unsigned long delta_ns,
                          const enum hrtimer_mode mode, int wakeup);
 
+#ifdef CONFIG_ARCH_HAS_SEND_PULL_TIMERS
+extern void hrtimer_start_on_info_init(struct hrtimer_start_on_info *info);
+extern int hrtimer_start_on(int cpu, struct hrtimer_start_on_info *info,
+                        struct hrtimer *timer, ktime_t time,
+                        const enum hrtimer_mode mode);
+#endif
+
 extern int hrtimer_cancel(struct hrtimer *timer);
 extern int hrtimer_try_to_cancel(struct hrtimer *timer);
 
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 1e2a6db2d7dd..c9ac4fc837ba 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -38,6 +38,7 @@
 #define SCHED_BATCH             3
 /* SCHED_ISO: reserved but not implemented yet */
 #define SCHED_IDLE              5
+#define SCHED_LITMUS            6
 /* Can be ORed in to make sure the process is reverted back to SCHED_NORMAL on fork */
 #define SCHED_RESET_ON_FORK     0x40000000
 
@@ -94,6 +95,9 @@ struct sched_param {
 
 #include <asm/processor.h>
 
+#include <litmus/rt_param.h>
+#include <litmus/preempt.h>
+
 struct exec_domain;
 struct futex_pi_state;
 struct robust_list_head;
@@ -1159,6 +1163,7 @@ struct sched_rt_entity {
 };
 
 struct rcu_node;
+struct od_table_entry;
 
 struct task_struct {
         volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
@@ -1243,9 +1248,9 @@ struct task_struct {
         unsigned long stack_canary;
 #endif
 
-        /* 
+        /*
          * pointers to (original) parent process, youngest child, younger sibling,
-         * older sibling, respectively.  (p->father can be replaced with 
+         * older sibling, respectively.  (p->father can be replaced with
          * p->real_parent->pid)
          */
         struct task_struct *real_parent; /* real parent process */
@@ -1453,6 +1458,13 @@ struct task_struct {
         int make_it_fail;
 #endif
         struct prop_local_single dirties;
+
+        /* LITMUS RT parameters and state */
+        struct rt_param rt_param;
+
+        /* references to PI semaphores, etc. */
+        struct od_table_entry *od_table;
+
 #ifdef CONFIG_LATENCYTOP
         int latency_record_count;
         struct latency_record latency_record[LT_SAVECOUNT];
@@ -2014,7 +2026,7 @@ static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, s
         spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
 
         return ret;
-}       
+}
 
 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
                               sigset_t *mask);
@@ -2290,6 +2302,7 @@ static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
 static inline void set_tsk_need_resched(struct task_struct *tsk)
 {
         set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
+        sched_state_will_schedule(tsk);
 }
 
 static inline void clear_tsk_need_resched(struct task_struct *tsk)
diff --git a/include/linux/smp.h b/include/linux/smp.h
index cfa2d20e35f1..f86d40768e7f 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -80,6 +80,11 @@ int smp_call_function_any(const struct cpumask *mask,
                           void (*func)(void *info), void *info, int wait);
 
 /*
+ * sends a 'pull timer' event to a remote CPU
+ */
+extern void smp_send_pull_timers(int cpu);
+
+/*
  * Generic and arch helpers
  */
 #ifdef CONFIG_USE_GENERIC_SMP_HELPERS
diff --git a/include/linux/tick.h b/include/linux/tick.h
index b232ccc0ee29..1e29bd5b18af 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -74,6 +74,11 @@ extern int tick_is_oneshot_available(void);
 extern struct tick_device *tick_get_device(int cpu);
 
 # ifdef CONFIG_HIGH_RES_TIMERS
+/* LITMUS^RT tick alignment */
+#define LINUX_DEFAULT_TICKS     0
+#define LITMUS_ALIGNED_TICKS    1
+#define LITMUS_STAGGERED_TICKS  2
+
 extern int tick_init_highres(void);
 extern int tick_program_event(ktime_t expires, int force);
 extern void tick_setup_sched_timer(void);
diff --git a/include/litmus/bheap.h b/include/litmus/bheap.h
new file mode 100644
index 000000000000..cf4864a498d8
--- /dev/null
+++ b/include/litmus/bheap.h
@@ -0,0 +1,77 @@
+/* bheaps.h -- Binomial Heaps
+ *
+ * (c) 2008, 2009 Bjoern Brandenburg
+ */
+
+#ifndef BHEAP_H
+#define BHEAP_H
+
+#define NOT_IN_HEAP UINT_MAX
+
+struct bheap_node {
+        struct bheap_node*      parent;
+        struct bheap_node*      next;
+        struct bheap_node*      child;
+
+        unsigned int            degree;
+        void*                   value;
+        struct bheap_node**     ref;
+};
+
+struct bheap {
+        struct bheap_node*      head;
+        /* We cache the minimum of the heap.
+         * This speeds up repeated peek operations.
+         */
+        struct bheap_node*      min;
+};
+
+typedef int (*bheap_prio_t)(struct bheap_node* a, struct bheap_node* b);
+
+void bheap_init(struct bheap* heap);
+void bheap_node_init(struct bheap_node** ref_to_bheap_node_ptr, void* value);
+
+static inline int bheap_node_in_heap(struct bheap_node* h)
+{
+        return h->degree != NOT_IN_HEAP;
+}
+
+static inline int bheap_empty(struct bheap* heap)
+{
+        return heap->head == NULL && heap->min == NULL;
+}
+
+/* insert (and reinitialize) a node into the heap */
+void bheap_insert(bheap_prio_t higher_prio,
+                 struct bheap* heap,
+                 struct bheap_node* node);
+
+/* merge addition into target */
+void bheap_union(bheap_prio_t higher_prio,
+                struct bheap* target,
+                struct bheap* addition);
+
+struct bheap_node* bheap_peek(bheap_prio_t higher_prio,
+                            struct bheap* heap);
+
+struct bheap_node* bheap_take(bheap_prio_t higher_prio,
+                            struct bheap* heap);
+
+void bheap_uncache_min(bheap_prio_t higher_prio, struct bheap* heap);
+int  bheap_decrease(bheap_prio_t higher_prio, struct bheap_node* node);
+
+void bheap_delete(bheap_prio_t higher_prio,
+                 struct bheap* heap,
+                 struct bheap_node* node);
+
+/* allocate from memcache */
+struct bheap_node* bheap_node_alloc(int gfp_flags);
+void bheap_node_free(struct bheap_node* hn);
+
+/* allocate a heap node for value and insert into the heap */
+int bheap_add(bheap_prio_t higher_prio, struct bheap* heap,
+             void* value, int gfp_flags);
+
+void* bheap_take_del(bheap_prio_t higher_prio,
+                    struct bheap* heap);
+#endif
diff --git a/include/litmus/budget.h b/include/litmus/budget.h
new file mode 100644
index 000000000000..732530e63491
--- /dev/null
+++ b/include/litmus/budget.h
@@ -0,0 +1,8 @@
+#ifndef _LITMUS_BUDGET_H_
+#define _LITMUS_BUDGET_H_
+
+/* Update the per-processor enforcement timer (arm/reproram/cancel) for
+ * the next task. */
+void update_enforcement_timer(struct task_struct* t);
+
+#endif
diff --git a/include/litmus/clustered.h b/include/litmus/clustered.h
new file mode 100644
index 000000000000..0c18dcb15e6c
--- /dev/null
+++ b/include/litmus/clustered.h
@@ -0,0 +1,44 @@
+#ifndef CLUSTERED_H
+#define CLUSTERED_H
+
+/* Which cache level should be used to group CPUs into clusters?
+ * GLOBAL_CLUSTER means that all CPUs form a single cluster (just like under
+ * global scheduling).
+ */
+enum cache_level {
+        GLOBAL_CLUSTER = 0,
+        L1_CLUSTER     = 1,
+        L2_CLUSTER     = 2,
+        L3_CLUSTER     = 3
+};
+
+int parse_cache_level(const char *str, enum cache_level *level);
+const char* cache_level_name(enum cache_level level);
+
+/* expose a cache level in a /proc dir */
+struct proc_dir_entry* create_cluster_file(struct proc_dir_entry* parent,
+                                           enum cache_level* level);
+
+
+
+struct scheduling_cluster {
+        unsigned int id;
+        /* list of CPUs that are part of this cluster */
+        struct list_head cpus;
+};
+
+struct cluster_cpu {
+        unsigned int id; /* which CPU is this? */
+        struct list_head cluster_list; /* List of the CPUs in this cluster. */
+        struct scheduling_cluster* cluster; /* The cluster that this CPU belongs to. */
+};
+
+int get_cluster_size(enum cache_level level);
+
+int assign_cpus_to_clusters(enum cache_level level,
+                            struct scheduling_cluster* clusters[],
+                            unsigned int num_clusters,
+                            struct cluster_cpu* cpus[],
+                            unsigned int num_cpus);
+
+#endif
diff --git a/include/litmus/debug_trace.h b/include/litmus/debug_trace.h
new file mode 100644
index 000000000000..48d086d5a44c
--- /dev/null
+++ b/include/litmus/debug_trace.h
@@ -0,0 +1,37 @@
+#ifndef LITMUS_DEBUG_TRACE_H
+#define LITMUS_DEBUG_TRACE_H
+
+#ifdef CONFIG_SCHED_DEBUG_TRACE
+void sched_trace_log_message(const char* fmt, ...);
+void dump_trace_buffer(int max);
+#else
+
+#define sched_trace_log_message(fmt, ...)
+
+#endif
+
+extern atomic_t __log_seq_no;
+
+#ifdef CONFIG_SCHED_DEBUG_TRACE_CALLER
+#define TRACE_PREFIX "%d P%d [%s@%s:%d]: "
+#define TRACE_ARGS  atomic_add_return(1, &__log_seq_no),        \
+                raw_smp_processor_id(),                         \
+                __FUNCTION__, __FILE__, __LINE__
+#else
+#define TRACE_PREFIX "%d P%d: "
+#define TRACE_ARGS  atomic_add_return(1, &__log_seq_no), \
+                raw_smp_processor_id()
+#endif
+
+#define TRACE(fmt, args...)                                             \
+        sched_trace_log_message(TRACE_PREFIX fmt,                       \
+                                TRACE_ARGS,  ## args)
+
+#define TRACE_TASK(t, fmt, args...)                     \
+        TRACE("(%s/%d:%d) " fmt, (t)->comm, (t)->pid,   \
+              (t)->rt_param.job_params.job_no,  ##args)
+
+#define TRACE_CUR(fmt, args...) \
+        TRACE_TASK(current, fmt, ## args)
+
+#endif
diff --git a/include/litmus/edf_common.h b/include/litmus/edf_common.h
new file mode 100644
index 000000000000..2c4266f77c03
--- /dev/null
+++ b/include/litmus/edf_common.h
@@ -0,0 +1,33 @@
+/*
+ * EDF common data structures and utility functions shared by all EDF
+ * based scheduler plugins
+ */
+
+/* CLEANUP: Add comments and make it less messy.
+ *
+ */
+
+#ifndef __UNC_EDF_COMMON_H__
+#define __UNC_EDF_COMMON_H__
+
+#include <litmus/rt_domain.h>
+
+void edf_domain_init(rt_domain_t* rt, check_resched_needed_t resched,
+                     release_jobs_t release);
+
+int edf_higher_prio(struct task_struct* first,
+                    struct task_struct* second);
+
+#ifdef CONFIG_LITMUS_LOCKING
+/* priority comparison without priority inheritance */
+int edf_higher_base_prio(struct task_struct* first,
+                         struct task_struct* second);
+
+int edf_pending_order(struct bheap_node* a, struct bheap_node* b);
+#endif
+
+int edf_ready_order(struct bheap_node* a, struct bheap_node* b);
+
+int edf_preemption_needed(rt_domain_t* rt, struct task_struct *t);
+
+#endif
diff --git a/include/litmus/fdso.h b/include/litmus/fdso.h
new file mode 100644
index 000000000000..d1ee0d1142d8
--- /dev/null
+++ b/include/litmus/fdso.h
@@ -0,0 +1,77 @@
+/* fdso.h - file descriptor attached shared objects
+ *
+ * (c) 2007--2011 B. Brandenburg, LITMUS^RT project
+ */
+
+#ifndef _LINUX_FDSO_H_
+#define _LINUX_FDSO_H_
+
+#include <linux/list.h>
+#include <asm/atomic.h>
+
+#include <linux/fs.h>
+#include <linux/slab.h>
+
+#define MAX_OBJECT_DESCRIPTORS 85
+
+typedef enum  {
+        MIN_OBJ_TYPE    = 0,
+
+        FMLP_SEM        = 0,
+        SRP_SEM         = 1,
+
+        MPCP_SEM        = 2,
+        MPCP_VS_SEM     = 3,
+        DPCP_SEM        = 4,
+
+        OMLP_SEM        = 5,
+
+        MAX_OBJ_TYPE    = 5
+} obj_type_t;
+
+struct inode_obj_id {
+        struct list_head        list;
+        atomic_t                count;
+        struct inode*           inode;
+
+        obj_type_t              type;
+        void*                   obj;
+        unsigned int            id;
+};
+
+struct fdso_ops;
+
+struct od_table_entry {
+        unsigned int            used;
+
+        struct inode_obj_id*    obj;
+        const struct fdso_ops*  class;
+};
+
+struct fdso_ops {
+        int   (*create)(void** obj_ref, obj_type_t type, void* __user);
+        void  (*destroy)(obj_type_t type, void*);
+        int   (*open)   (struct od_table_entry*, void* __user);
+        int   (*close)  (struct od_table_entry*);
+};
+
+/* translate a userspace supplied od into the raw table entry
+ * returns NULL if od is invalid
+ */
+struct od_table_entry* get_entry_for_od(int od);
+
+/* translate a userspace supplied od into the associated object
+ * returns NULL if od is invalid
+ */
+static inline void* od_lookup(int od, obj_type_t type)
+{
+        struct od_table_entry* e = get_entry_for_od(od);
+        return e && e->obj->type == type ? e->obj->obj : NULL;
+}
+
+#define lookup_fmlp_sem(od)((struct pi_semaphore*)  od_lookup(od, FMLP_SEM))
+#define lookup_srp_sem(od) ((struct srp_semaphore*) od_lookup(od, SRP_SEM))
+#define lookup_ics(od)     ((struct ics*)           od_lookup(od, ICS_ID))
+
+
+#endif
diff --git a/include/litmus/feather_buffer.h b/include/litmus/feather_buffer.h
new file mode 100644
index 000000000000..6c18277fdfc9
--- /dev/null
+++ b/include/litmus/feather_buffer.h
@@ -0,0 +1,94 @@
+#ifndef _FEATHER_BUFFER_H_
+#define _FEATHER_BUFFER_H_
+
+/* requires UINT_MAX and memcpy */
+
+#define SLOT_FREE       0
+#define SLOT_BUSY       1
+#define SLOT_READY      2
+
+struct ft_buffer {
+        unsigned int    slot_count;
+        unsigned int    slot_size;
+
+        int             free_count;
+        unsigned int    write_idx;
+        unsigned int    read_idx;
+
+        char*           slots;
+        void*           buffer_mem;
+        unsigned int    failed_writes;
+};
+
+static inline int init_ft_buffer(struct ft_buffer*      buf,
+                                 unsigned int           slot_count,
+                                 unsigned int           slot_size,
+                                 char*                  slots,
+                                 void*                  buffer_mem)
+{
+        int i = 0;
+        if (!slot_count || UINT_MAX % slot_count != slot_count - 1) {
+                /* The slot count must divide UNIT_MAX + 1 so that when it
+                 * wraps around the index correctly points to 0.
+                 */
+                return 0;
+        } else {
+                buf->slot_count    = slot_count;
+                buf->slot_size     = slot_size;
+                buf->slots         = slots;
+                buf->buffer_mem    = buffer_mem;
+                buf->free_count    = slot_count;
+                buf->write_idx     = 0;
+                buf->read_idx      = 0;
+                buf->failed_writes = 0;
+                for (i = 0; i < slot_count; i++)
+                        buf->slots[i] = SLOT_FREE;
+                return 1;
+        }
+}
+
+static inline int ft_buffer_start_write(struct ft_buffer* buf, void **ptr)
+{
+        int free = fetch_and_dec(&buf->free_count);
+        unsigned int idx;
+        if (free <= 0) {
+                fetch_and_inc(&buf->free_count);
+                *ptr = 0;
+                fetch_and_inc(&buf->failed_writes);
+                return 0;
+        } else {
+                idx  = fetch_and_inc((int*) &buf->write_idx) % buf->slot_count;
+                buf->slots[idx] = SLOT_BUSY;
+                *ptr = ((char*) buf->buffer_mem) + idx * buf->slot_size;
+                return 1;
+        }
+}
+
+static inline void ft_buffer_finish_write(struct ft_buffer* buf, void *ptr)
+{
+        unsigned int idx = ((char*) ptr - (char*) buf->buffer_mem) / buf->slot_size;
+        buf->slots[idx]  = SLOT_READY;
+}
+
+
+/* exclusive reader access is assumed */
+static inline int ft_buffer_read(struct ft_buffer* buf, void* dest)
+{
+        unsigned int idx;
+        if (buf->free_count == buf->slot_count)
+                /* nothing available */
+                return 0;
+        idx = buf->read_idx % buf->slot_count;
+        if (buf->slots[idx] == SLOT_READY) {
+                memcpy(dest, ((char*) buf->buffer_mem) + idx * buf->slot_size,
+                       buf->slot_size);
+                buf->slots[idx] = SLOT_FREE;
+                buf->read_idx++;
+                fetch_and_inc(&buf->free_count);
+                return 1;
+        } else
+                return 0;
+}
+
+
+#endif
diff --git a/include/litmus/feather_trace.h b/include/litmus/feather_trace.h
new file mode 100644
index 000000000000..028dfb206fb0
--- /dev/null
+++ b/include/litmus/feather_trace.h
@@ -0,0 +1,65 @@
+#ifndef _FEATHER_TRACE_H_
+#define _FEATHER_TRACE_H_
+
+#include <asm/atomic.h>
+
+int ft_enable_event(unsigned long id);
+int ft_disable_event(unsigned long id);
+int ft_is_event_enabled(unsigned long id);
+int ft_disable_all_events(void);
+
+/* atomic_* funcitons are inline anyway */
+static inline int fetch_and_inc(int *val)
+{
+        return atomic_add_return(1, (atomic_t*) val) - 1;
+}
+
+static inline int fetch_and_dec(int *val)
+{
+        return atomic_sub_return(1, (atomic_t*) val) + 1;
+}
+
+/* Don't use rewriting implementation if kernel text pages are read-only.
+ * Ftrace gets around this by using the identity mapping, but that's more
+ * effort that is warrented right now for Feather-Trace.
+ * Eventually, it may make sense to replace Feather-Trace with ftrace.
+ */
+#if defined(CONFIG_ARCH_HAS_FEATHER_TRACE) && !defined(CONFIG_DEBUG_RODATA)
+
+#include <asm/feather_trace.h>
+
+#else /* !__ARCH_HAS_FEATHER_TRACE */
+
+/* provide default implementation */
+
+#include <asm/timex.h> /* for get_cycles() */
+
+static inline unsigned long long ft_timestamp(void)
+{
+        return get_cycles();
+}
+
+#define feather_callback
+
+#define MAX_EVENTS 1024
+
+extern int ft_events[MAX_EVENTS];
+
+#define ft_event(id, callback) \
+        if (ft_events[id]) callback();
+
+#define ft_event0(id, callback) \
+        if (ft_events[id]) callback(id);
+
+#define ft_event1(id, callback, param) \
+        if (ft_events[id]) callback(id, param);
+
+#define ft_event2(id, callback, param, param2) \
+        if (ft_events[id]) callback(id, param, param2);
+
+#define ft_event3(id, callback, p, p2, p3) \
+        if (ft_events[id]) callback(id, p, p2, p3);
+
+#endif /* __ARCH_HAS_FEATHER_TRACE */
+
+#endif
diff --git a/include/litmus/fp_common.h b/include/litmus/fp_common.h
new file mode 100644
index 000000000000..dd1f7bf1e347
--- /dev/null
+++ b/include/litmus/fp_common.h
@@ -0,0 +1,105 @@
+/* Fixed-priority scheduler support.
+ */
+
+#ifndef __FP_COMMON_H__
+#define __FP_COMMON_H__
+
+#include <litmus/rt_domain.h>
+
+#include <asm/bitops.h>
+
+
+void fp_domain_init(rt_domain_t* rt, check_resched_needed_t resched,
+                    release_jobs_t release);
+
+int fp_higher_prio(struct task_struct* first,
+                   struct task_struct* second);
+
+int fp_ready_order(struct bheap_node* a, struct bheap_node* b);
+
+#define FP_PRIO_BIT_WORDS (LITMUS_MAX_PRIORITY / BITS_PER_LONG)
+
+#if (LITMUS_MAX_PRIORITY % BITS_PER_LONG)
+#error LITMUS_MAX_PRIORITY must be a multiple of BITS_PER_LONG
+#endif
+
+/* bitmask-inexed priority queue */
+struct fp_prio_queue {
+        unsigned long   bitmask[FP_PRIO_BIT_WORDS];
+        struct bheap    queue[LITMUS_MAX_PRIORITY];
+};
+
+void fp_prio_queue_init(struct fp_prio_queue* q);
+
+static inline void fpq_set(struct fp_prio_queue* q, unsigned int index)
+{
+        unsigned long *word = q->bitmask + (index / BITS_PER_LONG);
+        __set_bit(index % BITS_PER_LONG, word);
+}
+
+static inline void fpq_clear(struct fp_prio_queue* q, unsigned int index)
+{
+        unsigned long *word = q->bitmask + (index / BITS_PER_LONG);
+        __clear_bit(index % BITS_PER_LONG, word);
+}
+
+static inline unsigned int fpq_find(struct fp_prio_queue* q)
+{
+        int i;
+
+        /* loop optimizer should unroll this */
+        for (i = 0; i < FP_PRIO_BIT_WORDS; i++)
+                if (q->bitmask[i])
+                        return __ffs(q->bitmask[i]) + i * BITS_PER_LONG;
+
+        return LITMUS_MAX_PRIORITY; /* nothing found */
+}
+
+static inline void fp_prio_add(struct fp_prio_queue* q, struct task_struct* t, unsigned int index)
+{
+
+        BUG_ON(bheap_node_in_heap(tsk_rt(t)->heap_node));
+
+        fpq_set(q, index);
+        bheap_insert(fp_ready_order, &q->queue[index], tsk_rt(t)->heap_node);
+}
+
+static inline void fp_prio_remove(struct fp_prio_queue* q, struct task_struct* t, unsigned int index)
+{
+        BUG_ON(!is_queued(t));
+
+        bheap_delete(fp_ready_order, &q->queue[index], tsk_rt(t)->heap_node);
+        if (likely(bheap_empty(&q->queue[index])))
+                fpq_clear(q, index);
+}
+
+static inline struct task_struct* fp_prio_peek(struct fp_prio_queue* q)
+{
+        unsigned int idx = fpq_find(q);
+        struct bheap_node* hn;
+
+        if (idx < LITMUS_MAX_PRIORITY) {
+                hn = bheap_peek(fp_ready_order, &q->queue[idx]);
+                return bheap2task(hn);
+        } else
+                return NULL;
+}
+
+static inline struct task_struct* fp_prio_take(struct fp_prio_queue* q)
+{
+        unsigned int idx = fpq_find(q);
+        struct bheap_node* hn;
+
+        if (idx < LITMUS_MAX_PRIORITY) {
+                hn = bheap_take(fp_ready_order, &q->queue[idx]);
+                if (likely(bheap_empty(&q->queue[idx])))
+                        fpq_clear(q, idx);
+                return bheap2task(hn);
+        } else
+                return NULL;
+}
+
+int fp_preemption_needed(struct fp_prio_queue*  q, struct task_struct *t);
+
+
+#endif
diff --git a/include/litmus/ftdev.h b/include/litmus/ftdev.h
new file mode 100644
index 000000000000..0b959874dd70
--- /dev/null
+++ b/include/litmus/ftdev.h
@@ -0,0 +1,55 @@
+#ifndef _LITMUS_FTDEV_H_
+#define _LITMUS_FTDEV_H_
+
+#include <litmus/feather_trace.h>
+#include <litmus/feather_buffer.h>
+#include <linux/mutex.h>
+#include <linux/cdev.h>
+
+#define FTDEV_ENABLE_CMD        0
+#define FTDEV_DISABLE_CMD       1
+
+struct ftdev;
+
+/* return 0 if buffer can be opened, otherwise -$REASON */
+typedef int  (*ftdev_can_open_t)(struct ftdev* dev, unsigned int buf_no);
+/* return 0 on success, otherwise -$REASON */
+typedef int  (*ftdev_alloc_t)(struct ftdev* dev, unsigned int buf_no);
+typedef void (*ftdev_free_t)(struct ftdev* dev, unsigned int buf_no);
+/* Let devices handle writes from userspace. No synchronization provided. */
+typedef ssize_t (*ftdev_write_t)(struct ft_buffer* buf, size_t len, const char __user *from);
+
+struct ftdev_event;
+
+struct ftdev_minor {
+        struct ft_buffer*       buf;
+        unsigned int            readers;
+        struct mutex            lock;
+        /* FIXME: filter for authorized events */
+        struct ftdev_event*     events;
+        struct device*          device;
+        struct ftdev*           ftdev;
+};
+
+struct ftdev {
+        dev_t                   major;
+        struct cdev             cdev;
+        struct class*           class;
+        const char*             name;
+        struct ftdev_minor*     minor;
+        unsigned int            minor_cnt;
+        ftdev_alloc_t           alloc;
+        ftdev_free_t            free;
+        ftdev_can_open_t        can_open;
+        ftdev_write_t           write;
+};
+
+struct ft_buffer* alloc_ft_buffer(unsigned int count, size_t size);
+void free_ft_buffer(struct ft_buffer* buf);
+
+int ftdev_init( struct ftdev* ftdev, struct module* owner,
+                const int minor_cnt, const char* name);
+void ftdev_exit(struct ftdev* ftdev);
+int register_ftdev(struct ftdev* ftdev);
+
+#endif
diff --git a/include/litmus/jobs.h b/include/litmus/jobs.h
new file mode 100644
index 000000000000..9bd361ef3943
--- /dev/null
+++ b/include/litmus/jobs.h
@@ -0,0 +1,9 @@
+#ifndef __LITMUS_JOBS_H__
+#define __LITMUS_JOBS_H__
+
+void prepare_for_next_period(struct task_struct *t);
+void release_at(struct task_struct *t, lt_t start);
+long complete_job(void);
+
+#endif
+
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
diff --git a/include/litmus/litmus_proc.h b/include/litmus/litmus_proc.h
new file mode 100644
index 000000000000..6800e725d48c
--- /dev/null
+++ b/include/litmus/litmus_proc.h
@@ -0,0 +1,25 @@
+#include <litmus/sched_plugin.h>
+#include <linux/proc_fs.h>
+
+int __init init_litmus_proc(void);
+void exit_litmus_proc(void);
+
+/*
+ * On success, returns 0 and sets the pointer to the location of the new
+ * proc dir entry, otherwise returns an error code and sets pde to NULL.
+ */
+long make_plugin_proc_dir(struct sched_plugin* plugin,
+                struct proc_dir_entry** pde);
+
+/*
+ * Plugins should deallocate all child proc directory entries before
+ * calling this, to avoid memory leaks.
+ */
+void remove_plugin_proc_dir(struct sched_plugin* plugin);
+
+
+/* Copy at most size-1 bytes from ubuf into kbuf, null-terminate buf, and
+ * remove a '\n' if present. Returns the number of bytes that were read or
+ * -EFAULT. */
+int copy_and_chomp(char *kbuf, unsigned long ksize,
+                   __user const char* ubuf, unsigned long ulength);
diff --git a/include/litmus/locking.h b/include/litmus/locking.h
new file mode 100644
index 000000000000..4d7b870cb443
--- /dev/null
+++ b/include/litmus/locking.h
@@ -0,0 +1,28 @@
+#ifndef LITMUS_LOCKING_H
+#define LITMUS_LOCKING_H
+
+struct litmus_lock_ops;
+
+/* Generic base struct for LITMUS^RT userspace semaphores.
+ * This structure should be embedded in protocol-specific semaphores.
+ */
+struct litmus_lock {
+        struct litmus_lock_ops *ops;
+        int type;
+};
+
+struct litmus_lock_ops {
+        /* Current task tries to obtain / drop a reference to a lock.
+         * Optional methods, allowed by default. */
+        int (*open)(struct litmus_lock*, void* __user);
+        int (*close)(struct litmus_lock*);
+
+        /* Current tries to lock/unlock this lock (mandatory methods). */
+        int (*lock)(struct litmus_lock*);
+        int (*unlock)(struct litmus_lock*);
+
+        /* The lock is no longer being referenced (mandatory method). */
+        void (*deallocate)(struct litmus_lock*);
+};
+
+#endif
diff --git a/include/litmus/preempt.h b/include/litmus/preempt.h
new file mode 100644
index 000000000000..f3cf29ad87ee
--- /dev/null
+++ b/include/litmus/preempt.h
@@ -0,0 +1,165 @@
+#ifndef LITMUS_PREEMPT_H
+#define LITMUS_PREEMPT_H
+
+#include <linux/types.h>
+#include <linux/cache.h>
+#include <linux/percpu.h>
+#include <asm/atomic.h>
+
+#include <litmus/debug_trace.h>
+
+extern DEFINE_PER_CPU_SHARED_ALIGNED(atomic_t, resched_state);
+
+//#ifdef CONFIG_DEBUG_KERNEL
+#if 0
+const char* sched_state_name(int s);
+#define TRACE_STATE(fmt, args...) TRACE("SCHED_STATE " fmt, args)
+#else
+#define TRACE_STATE(fmt, args...) /* ignore */
+#endif
+
+#define VERIFY_SCHED_STATE(x)                                           \
+        do { int __s = get_sched_state();                               \
+                if ((__s & (x)) == 0)                                   \
+                        TRACE_STATE("INVALID s=0x%x (%s) not "          \
+                                    "in 0x%x (%s) [%s]\n",              \
+                                    __s, sched_state_name(__s),         \
+                                    (x), #x, __FUNCTION__);             \
+        } while (0);
+
+#define TRACE_SCHED_STATE_CHANGE(x, y, cpu)                             \
+        TRACE_STATE("[P%d] 0x%x (%s) -> 0x%x (%s)\n",                   \
+                    cpu,  (x), sched_state_name(x),                     \
+                    (y), sched_state_name(y))
+
+
+typedef enum scheduling_state {
+        TASK_SCHEDULED    = (1 << 0),  /* The currently scheduled task is the one that
+                                        * should be scheduled, and the processor does not
+                                        * plan to invoke schedule(). */
+        SHOULD_SCHEDULE   = (1 << 1),  /* A remote processor has determined that the
+                                        * processor should reschedule, but this has not
+                                        * been communicated yet (IPI still pending). */
+        WILL_SCHEDULE     = (1 << 2),  /* The processor has noticed that it has to
+                                        * reschedule and will do so shortly. */
+        TASK_PICKED       = (1 << 3),  /* The processor is currently executing schedule(),
+                                        * has selected a new task to schedule, but has not
+                                        * yet performed the actual context switch. */
+        PICKED_WRONG_TASK = (1 << 4),  /* The processor has not yet performed the context
+                                        * switch, but a remote processor has already
+                                        * determined that a higher-priority task became
+                                        * eligible after the task was picked. */
+} sched_state_t;
+
+static inline sched_state_t get_sched_state_on(int cpu)
+{
+        return atomic_read(&per_cpu(resched_state, cpu));
+}
+
+static inline sched_state_t get_sched_state(void)
+{
+        return atomic_read(&__get_cpu_var(resched_state));
+}
+
+static inline int is_in_sched_state(int possible_states)
+{
+        return get_sched_state() & possible_states;
+}
+
+static inline int cpu_is_in_sched_state(int cpu, int possible_states)
+{
+        return get_sched_state_on(cpu) & possible_states;
+}
+
+static inline void set_sched_state(sched_state_t s)
+{
+        TRACE_SCHED_STATE_CHANGE(get_sched_state(), s, smp_processor_id());
+        atomic_set(&__get_cpu_var(resched_state), s);
+}
+
+static inline int sched_state_transition(sched_state_t from, sched_state_t to)
+{
+        sched_state_t old_state;
+
+        old_state = atomic_cmpxchg(&__get_cpu_var(resched_state), from, to);
+        if (old_state == from) {
+                TRACE_SCHED_STATE_CHANGE(from, to, smp_processor_id());
+                return 1;
+        } else
+                return 0;
+}
+
+static inline int sched_state_transition_on(int cpu,
+                                            sched_state_t from,
+                                            sched_state_t to)
+{
+        sched_state_t old_state;
+
+        old_state = atomic_cmpxchg(&per_cpu(resched_state, cpu), from, to);
+        if (old_state == from) {
+                TRACE_SCHED_STATE_CHANGE(from, to, cpu);
+                return 1;
+        } else
+                return 0;
+}
+
+/* Plugins must call this function after they have decided which job to
+ * schedule next.  IMPORTANT: this function must be called while still holding
+ * the lock that is used to serialize scheduling decisions.
+ *
+ * (Ideally, we would like to use runqueue locks for this purpose, but that
+ * would lead to deadlocks with the migration code.)
+ */
+static inline void sched_state_task_picked(void)
+{
+        VERIFY_SCHED_STATE(WILL_SCHEDULE);
+
+        /* WILL_SCHEDULE has only a local tansition => simple store is ok */
+        set_sched_state(TASK_PICKED);
+}
+
+static inline void sched_state_entered_schedule(void)
+{
+        /* Update state for the case that we entered schedule() not due to
+         * set_tsk_need_resched() */
+        set_sched_state(WILL_SCHEDULE);
+}
+
+/* Called by schedule() to check if the scheduling decision is still valid
+ * after a context switch. Returns 1 if the CPU needs to reschdule. */
+static inline int sched_state_validate_switch(void)
+{
+        int left_state_ok = 0;
+
+        VERIFY_SCHED_STATE(PICKED_WRONG_TASK | TASK_PICKED);
+
+        if (is_in_sched_state(TASK_PICKED)) {
+                /* Might be good; let's try to transition out of this
+                 * state. This must be done atomically since remote processors
+                 * may try to change the state, too. */
+                left_state_ok = sched_state_transition(TASK_PICKED, TASK_SCHEDULED);
+        }
+
+        if (!left_state_ok) {
+                /* We raced with a higher-priority task arrival => not
+                 * valid. The CPU needs to reschedule. */
+                set_sched_state(WILL_SCHEDULE);
+                return 1;
+        } else
+                return 0;
+}
+
+/* State transition events. See litmus/preempt.c for details. */
+void sched_state_will_schedule(struct task_struct* tsk);
+void sched_state_ipi(void);
+/* Cause a CPU (remote or local) to reschedule. */
+void litmus_reschedule(int cpu);
+void litmus_reschedule_local(void);
+
+#ifdef CONFIG_DEBUG_KERNEL
+void sched_state_plugin_check(void);
+#else
+#define sched_state_plugin_check() /* no check */
+#endif
+
+#endif
diff --git a/include/litmus/rt_domain.h b/include/litmus/rt_domain.h
new file mode 100644
index 000000000000..ac249292e866
--- /dev/null
+++ b/include/litmus/rt_domain.h
@@ -0,0 +1,182 @@
+/* CLEANUP: Add comments and make it less messy.
+ *
+ */
+
+#ifndef __UNC_RT_DOMAIN_H__
+#define __UNC_RT_DOMAIN_H__
+
+#include <litmus/bheap.h>
+
+#define RELEASE_QUEUE_SLOTS 127 /* prime */
+
+struct _rt_domain;
+
+typedef int (*check_resched_needed_t)(struct _rt_domain *rt);
+typedef void (*release_jobs_t)(struct _rt_domain *rt, struct bheap* tasks);
+
+struct release_queue {
+        /* each slot maintains a list of release heaps sorted
+         * by release time */
+        struct list_head                slot[RELEASE_QUEUE_SLOTS];
+};
+
+typedef struct _rt_domain {
+        /* runnable rt tasks are in here */
+        raw_spinlock_t                  ready_lock;
+        struct bheap                    ready_queue;
+
+        /* real-time tasks waiting for release are in here */
+        raw_spinlock_t                  release_lock;
+        struct release_queue            release_queue;
+
+#ifdef CONFIG_RELEASE_MASTER
+        int                             release_master;
+#endif
+
+        /* for moving tasks to the release queue */
+        raw_spinlock_t                  tobe_lock;
+        struct list_head                tobe_released;
+
+        /* how do we check if we need to kick another CPU? */
+        check_resched_needed_t          check_resched;
+
+        /* how do we release jobs? */
+        release_jobs_t                  release_jobs;
+
+        /* how are tasks ordered in the ready queue? */
+        bheap_prio_t                    order;
+} rt_domain_t;
+
+struct release_heap {
+        /* list_head for per-time-slot list */
+        struct list_head                list;
+        lt_t                            release_time;
+        /* all tasks to be released at release_time */
+        struct bheap                    heap;
+        /* used to trigger the release */
+        struct hrtimer                  timer;
+
+#ifdef CONFIG_RELEASE_MASTER
+        /* used to delegate releases */
+        struct hrtimer_start_on_info    info;
+#endif
+        /* required for the timer callback */
+        rt_domain_t*                    dom;
+};
+
+
+static inline struct task_struct* __next_ready(rt_domain_t* rt)
+{
+        struct bheap_node *hn = bheap_peek(rt->order, &rt->ready_queue);
+        if (hn)
+                return bheap2task(hn);
+        else
+                return NULL;
+}
+
+void rt_domain_init(rt_domain_t *rt, bheap_prio_t order,
+                    check_resched_needed_t check,
+                    release_jobs_t relase);
+
+void __add_ready(rt_domain_t* rt, struct task_struct *new);
+void __merge_ready(rt_domain_t* rt, struct bheap *tasks);
+void __add_release(rt_domain_t* rt, struct task_struct *task);
+
+static inline struct task_struct* __take_ready(rt_domain_t* rt)
+{
+        struct bheap_node* hn = bheap_take(rt->order, &rt->ready_queue);
+        if (hn)
+                return bheap2task(hn);
+        else
+                return NULL;
+}
+
+static inline struct task_struct* __peek_ready(rt_domain_t* rt)
+{
+        struct bheap_node* hn = bheap_peek(rt->order, &rt->ready_queue);
+        if (hn)
+                return bheap2task(hn);
+        else
+                return NULL;
+}
+
+static inline int  is_queued(struct task_struct *t)
+{
+        BUG_ON(!tsk_rt(t)->heap_node);
+        return bheap_node_in_heap(tsk_rt(t)->heap_node);
+}
+
+static inline void remove(rt_domain_t* rt, struct task_struct *t)
+{
+        bheap_delete(rt->order, &rt->ready_queue, tsk_rt(t)->heap_node);
+}
+
+static inline void add_ready(rt_domain_t* rt, struct task_struct *new)
+{
+        unsigned long flags;
+        /* first we need the write lock for rt_ready_queue */
+        raw_spin_lock_irqsave(&rt->ready_lock, flags);
+        __add_ready(rt, new);
+        raw_spin_unlock_irqrestore(&rt->ready_lock, flags);
+}
+
+static inline void merge_ready(rt_domain_t* rt, struct bheap* tasks)
+{
+        unsigned long flags;
+        raw_spin_lock_irqsave(&rt->ready_lock, flags);
+        __merge_ready(rt, tasks);
+        raw_spin_unlock_irqrestore(&rt->ready_lock, flags);
+}
+
+static inline struct task_struct* take_ready(rt_domain_t* rt)
+{
+        unsigned long flags;
+        struct task_struct* ret;
+        /* first we need the write lock for rt_ready_queue */
+        raw_spin_lock_irqsave(&rt->ready_lock, flags);
+        ret = __take_ready(rt);
+        raw_spin_unlock_irqrestore(&rt->ready_lock, flags);
+        return ret;
+}
+
+
+static inline void add_release(rt_domain_t* rt, struct task_struct *task)
+{
+        unsigned long flags;
+        raw_spin_lock_irqsave(&rt->tobe_lock, flags);
+        __add_release(rt, task);
+        raw_spin_unlock_irqrestore(&rt->tobe_lock, flags);
+}
+
+#ifdef CONFIG_RELEASE_MASTER
+void __add_release_on(rt_domain_t* rt, struct task_struct *task,
+                      int target_cpu);
+
+static inline void add_release_on(rt_domain_t* rt,
+                                  struct task_struct *task,
+                                  int target_cpu)
+{
+        unsigned long flags;
+        raw_spin_lock_irqsave(&rt->tobe_lock, flags);
+        __add_release_on(rt, task, target_cpu);
+        raw_spin_unlock_irqrestore(&rt->tobe_lock, flags);
+}
+#endif
+
+static inline int __jobs_pending(rt_domain_t* rt)
+{
+        return !bheap_empty(&rt->ready_queue);
+}
+
+static inline int jobs_pending(rt_domain_t* rt)
+{
+        unsigned long flags;
+        int ret;
+        /* first we need the write lock for rt_ready_queue */
+        raw_spin_lock_irqsave(&rt->ready_lock, flags);
+        ret = !bheap_empty(&rt->ready_queue);
+        raw_spin_unlock_irqrestore(&rt->ready_lock, flags);
+        return ret;
+}
+
+#endif
diff --git a/include/litmus/rt_param.h b/include/litmus/rt_param.h
new file mode 100644
index 000000000000..a23ce1524051
--- /dev/null
+++ b/include/litmus/rt_param.h
@@ -0,0 +1,228 @@
+/*
+ * Definition of the scheduler plugin interface.
+ *
+ */
+#ifndef _LINUX_RT_PARAM_H_
+#define _LINUX_RT_PARAM_H_
+
+/* Litmus time type. */
+typedef unsigned long long lt_t;
+
+static inline int lt_after(lt_t a, lt_t b)
+{
+        return ((long long) b) - ((long long) a) < 0;
+}
+#define lt_before(a, b) lt_after(b, a)
+
+static inline int lt_after_eq(lt_t a, lt_t b)
+{
+        return ((long long) a) - ((long long) b) >= 0;
+}
+#define lt_before_eq(a, b) lt_after_eq(b, a)
+
+/* different types of clients */
+typedef enum {
+        RT_CLASS_HARD,
+        RT_CLASS_SOFT,
+        RT_CLASS_BEST_EFFORT
+} task_class_t;
+
+typedef enum {
+        NO_ENFORCEMENT,      /* job may overrun unhindered */
+        QUANTUM_ENFORCEMENT, /* budgets are only checked on quantum boundaries */
+        PRECISE_ENFORCEMENT  /* NOT IMPLEMENTED - enforced with hrtimers */
+} budget_policy_t;
+
+#define LITMUS_MAX_PRIORITY 512
+
+struct rt_task {
+        lt_t            exec_cost;
+        lt_t            period;
+        lt_t            phase;
+        unsigned int    cpu;
+        unsigned int    priority;
+        task_class_t    cls;
+        budget_policy_t budget_policy; /* ignored by pfair */
+};
+
+union np_flag {
+        uint32_t raw;
+        struct {
+                /* Is the task currently in a non-preemptive section? */
+                uint32_t flag:31;
+                /* Should the task call into the scheduler? */
+                uint32_t preempt:1;
+        } np;
+};
+
+/* The definition of the data that is shared between the kernel and real-time
+ * tasks via a shared page (see litmus/ctrldev.c).
+ *
+ * WARNING: User space can write to this, so don't trust
+ * the correctness of the fields!
+ *
+ * This servees two purposes: to enable efficient signaling
+ * of non-preemptive sections (user->kernel) and
+ * delayed preemptions (kernel->user), and to export
+ * some real-time relevant statistics such as preemption and
+ * migration data to user space. We can't use a device to export
+ * statistics because we want to avoid system call overhead when
+ * determining preemption/migration overheads).
+ */
+struct control_page {
+        volatile union np_flag sched;
+
+        /* locking overhead tracing: time stamp prior to system call */
+        uint64_t ts_syscall_start; /* Feather-Trace cycles */
+
+        /* to be extended */
+};
+
+/* don't export internal data structures to user space (liblitmus) */
+#ifdef __KERNEL__
+
+struct _rt_domain;
+struct bheap_node;
+struct release_heap;
+
+struct rt_job {
+        /* Time instant the the job was or will be released.  */
+        lt_t    release;
+        /* What is the current deadline? */
+        lt_t    deadline;
+
+        /* How much service has this job received so far? */
+        lt_t    exec_time;
+
+        /* Which job is this. This is used to let user space
+         * specify which job to wait for, which is important if jobs
+         * overrun. If we just call sys_sleep_next_period() then we
+         * will unintentionally miss jobs after an overrun.
+         *
+         * Increase this sequence number when a job is released.
+         */
+        unsigned int    job_no;
+};
+
+struct pfair_param;
+
+/*      RT task parameters for scheduling extensions
+ *      These parameters are inherited during clone and therefore must
+ *      be explicitly set up before the task set is launched.
+ */
+struct rt_param {
+        /* is the task sleeping? */
+        unsigned int            flags:8;
+
+        /* do we need to check for srp blocking? */
+        unsigned int            srp_non_recurse:1;
+
+        /* is the task present? (true if it can be scheduled) */
+        unsigned int            present:1;
+
+#ifdef CONFIG_LITMUS_LOCKING
+        /* Is the task being priority-boosted by a locking protocol? */
+        unsigned int            priority_boosted:1;
+        /* If so, when did this start? */
+        lt_t                    boost_start_time;
+#endif
+
+        /* user controlled parameters */
+        struct rt_task          task_params;
+
+        /* timing parameters */
+        struct rt_job           job_params;
+
+        /* task representing the current "inherited" task
+         * priority, assigned by inherit_priority and
+         * return priority in the scheduler plugins.
+         * could point to self if PI does not result in
+         * an increased task priority.
+         */
+         struct task_struct*    inh_task;
+
+#ifdef CONFIG_NP_SECTION
+        /* For the FMLP under PSN-EDF, it is required to make the task
+         * non-preemptive from kernel space. In order not to interfere with
+         * user space, this counter indicates the kernel space np setting.
+         * kernel_np > 0 => task is non-preemptive
+         */
+        unsigned int    kernel_np;
+#endif
+
+        /* This field can be used by plugins to store where the task
+         * is currently scheduled. It is the responsibility of the
+         * plugin to avoid race conditions.
+         *
+         * This used by GSN-EDF and PFAIR.
+         */
+        volatile int            scheduled_on;
+
+        /* Is the stack of the task currently in use? This is updated by
+         * the LITMUS core.
+         *
+         * Be careful to avoid deadlocks!
+         */
+        volatile int            stack_in_use;
+
+        /* This field can be used by plugins to store where the task
+         * is currently linked. It is the responsibility of the plugin
+         * to avoid race conditions.
+         *
+         * Used by GSN-EDF.
+         */
+        volatile int            linked_on;
+
+        /* PFAIR/PD^2 state. Allocated on demand. */
+        struct pfair_param*     pfair;
+
+        /* Fields saved before BE->RT transition.
+         */
+        int old_policy;
+        int old_prio;
+
+        /* ready queue for this task */
+        struct _rt_domain* domain;
+
+        /* heap element for this task
+         *
+         * Warning: Don't statically allocate this node. The heap
+         *          implementation swaps these between tasks, thus after
+         *          dequeuing from a heap you may end up with a different node
+         *          then the one you had when enqueuing the task.  For the same
+         *          reason, don't obtain and store references to this node
+         *          other than this pointer (which is updated by the heap
+         *          implementation).
+         */
+        struct bheap_node*      heap_node;
+        struct release_heap*    rel_heap;
+
+#ifdef CONFIG_LITMUS_LOCKING
+        /* task in heap of pending jobs -- used by C-EDF for priority donation */
+        struct bheap_node*      pending_node;
+        /* is the job in a critical section or a wait queue?*/
+        unsigned int            request_incomplete;
+        /* is the job currently a donor? */
+        unsigned int            is_donor;
+        /* is this job suspended, waiting to become eligible? */
+        unsigned int            waiting_eligible;
+
+        int                     pending_on;
+#endif
+
+        /* Used by rt_domain to queue task in release list.
+         */
+        struct list_head list;
+
+        /* Pointer to the page shared between userspace and kernel. */
+        struct control_page * ctrl_page;
+};
+
+/*      Possible RT flags       */
+#define RT_F_RUNNING            0x00000000
+#define RT_F_SLEEP              0x00000001
+#define RT_F_EXIT_SEM           0x00000008
+
+#endif
+
+#endif
diff --git a/include/litmus/sched_plugin.h b/include/litmus/sched_plugin.h
new file mode 100644
index 000000000000..b5d1ae7bc3b6
--- /dev/null
+++ b/include/litmus/sched_plugin.h
@@ -0,0 +1,117 @@
+/*
+ * Definition of the scheduler plugin interface.
+ *
+ */
+#ifndef _LINUX_SCHED_PLUGIN_H_
+#define _LINUX_SCHED_PLUGIN_H_
+
+#include <linux/sched.h>
+
+#ifdef CONFIG_LITMUS_LOCKING
+#include <litmus/locking.h>
+#endif
+
+/************************ setup/tear down ********************/
+
+typedef long (*activate_plugin_t) (void);
+typedef long (*deactivate_plugin_t) (void);
+
+
+
+/********************* scheduler invocation ******************/
+
+/*  Plugin-specific realtime tick handler */
+typedef void (*scheduler_tick_t) (struct task_struct *cur);
+/* Novell make sched decision function */
+typedef struct task_struct* (*schedule_t)(struct task_struct * prev);
+/* Clean up after the task switch has occured.
+ * This function is called after every (even non-rt) task switch.
+ */
+typedef void (*finish_switch_t)(struct task_struct *prev);
+
+
+/********************* task state changes ********************/
+
+/* Called to setup a new real-time task.
+ * Release the first job, enqueue, etc.
+ * Task may already be running.
+ */
+typedef void (*task_new_t) (struct task_struct *task,
+                            int on_rq,
+                            int running);
+
+/* Called to re-introduce a task after blocking.
+ * Can potentially be called multiple times.
+ */
+typedef void (*task_wake_up_t) (struct task_struct *task);
+/* called to notify the plugin of a blocking real-time task
+ * it will only be called for real-time tasks and before schedule is called */
+typedef void (*task_block_t)  (struct task_struct *task);
+/* Called when a real-time task exits or changes to a different scheduling
+ * class.
+ * Free any allocated resources
+ */
+typedef void (*task_exit_t)    (struct task_struct *);
+
+/* called early before the caller  holds the runqueue lock */
+typedef void (*pre_setsched_t) (struct task_struct *, int policy);
+
+
+/* Called when the current task attempts to create a new lock of a given
+ * protocol type. */
+typedef long (*allocate_lock_t) (struct litmus_lock **lock, int type,
+                                 void* __user config);
+
+
+/********************* sys call backends  ********************/
+/* This function causes the caller to sleep until the next release */
+typedef long (*complete_job_t) (void);
+
+typedef long (*admit_task_t)(struct task_struct* tsk);
+
+typedef void (*release_at_t)(struct task_struct *t, lt_t start);
+
+struct sched_plugin {
+        struct list_head        list;
+        /*      basic info              */
+        char                    *plugin_name;
+
+        /*      setup                   */
+        activate_plugin_t       activate_plugin;
+        deactivate_plugin_t     deactivate_plugin;
+
+        /*      scheduler invocation    */
+        scheduler_tick_t        tick;
+        schedule_t              schedule;
+        finish_switch_t         finish_switch;
+
+        /*      syscall backend         */
+        complete_job_t          complete_job;
+        release_at_t            release_at;
+
+        /*      task state changes      */
+        admit_task_t            admit_task;
+
+        task_new_t              task_new;
+        task_wake_up_t          task_wake_up;
+        task_block_t            task_block;
+        task_exit_t             task_exit;
+
+        pre_setsched_t          pre_setsched;
+
+#ifdef CONFIG_LITMUS_LOCKING
+        /*      locking protocols       */
+        allocate_lock_t         allocate_lock;
+#endif
+} __attribute__ ((__aligned__(SMP_CACHE_BYTES)));
+
+
+extern struct sched_plugin *litmus;
+
+int register_sched_plugin(struct sched_plugin* plugin);
+struct sched_plugin* find_sched_plugin(const char* name);
+int print_sched_plugins(char* buf, int max);
+
+extern struct sched_plugin linux_sched_plugin;
+
+#endif
diff --git a/include/litmus/sched_plugin.h.rej b/include/litmus/sched_plugin.h.rej
new file mode 100644
index 000000000000..47e0c27c5061
--- /dev/null
+++ b/include/litmus/sched_plugin.h.rej
@@ -0,0 +1,22 @@
+--- include/litmus/sched_plugin.h
++++ include/litmus/sched_plugin.h
+@@ -53,6 +53,10 @@
+  */
+ typedef void (*task_exit_t)    (struct task_struct *);
+ 
++/* called early before the caller  holds the runqueue lock */
++typedef void (*pre_setsched_t) (struct task_struct *, int policy);
++
++
+ /* Called when the current task attempts to create a new lock of a given
+  * protocol type. */
+ typedef long (*allocate_lock_t) (struct litmus_lock **lock, int type,
+@@ -93,6 +97,8 @@
+        task_block_t            task_block;
+        task_exit_t             task_exit;
+ 
++       pre_setsched_t          pre_setsched;
++
+ #ifdef CONFIG_LITMUS_LOCKING
+        /*      locking protocols       */
+        allocate_lock_t         allocate_lock;
diff --git a/include/litmus/sched_trace.h b/include/litmus/sched_trace.h
new file mode 100644
index 000000000000..7ca34cb13881
--- /dev/null
+++ b/include/litmus/sched_trace.h
@@ -0,0 +1,200 @@
+/*
+ * sched_trace.h -- record scheduler events to a byte stream for offline analysis.
+ */
+#ifndef _LINUX_SCHED_TRACE_H_
+#define _LINUX_SCHED_TRACE_H_
+
+/* all times in nanoseconds */
+
+struct st_trace_header {
+        u8      type;           /* Of what type is this record?  */
+        u8      cpu;            /* On which CPU was it recorded? */
+        u16     pid;            /* PID of the task.              */
+        u32     job;            /* The job sequence number.      */
+};
+
+#define ST_NAME_LEN 16
+struct st_name_data {
+        char    cmd[ST_NAME_LEN];/* The name of the executable of this process. */
+};
+
+struct st_param_data {          /* regular params */
+        u32     wcet;
+        u32     period;
+        u32     phase;
+        u8      partition;
+        u8      class;
+        u8      __unused[2];
+};
+
+struct st_release_data {        /* A job is was/is going to be released. */
+        u64     release;        /* What's the release time?              */
+        u64     deadline;       /* By when must it finish?               */
+};
+
+struct st_assigned_data {       /* A job was asigned to a CPU.           */
+        u64     when;
+        u8      target;         /* Where should it execute?              */
+        u8      __unused[7];
+};
+
+struct st_switch_to_data {      /* A process was switched to on a given CPU.   */
+        u64     when;           /* When did this occur?                        */
+        u32     exec_time;      /* Time the current job has executed.          */
+        u8      __unused[4];
+
+};
+
+struct st_switch_away_data {    /* A process was switched away from on a given CPU. */
+        u64     when;
+        u64     exec_time;
+};
+
+struct st_completion_data {     /* A job completed. */
+        u64     when;
+        u8      forced:1;       /* Set to 1 if job overran and kernel advanced to the
+                                 * next task automatically; set to 0 otherwise.
+                                 */
+        u8      __uflags:7;
+        u8      __unused[7];
+};
+
+struct st_block_data {          /* A task blocks. */
+        u64     when;
+        u64     __unused;
+};
+
+struct st_resume_data {         /* A task resumes. */
+        u64     when;
+        u64     __unused;
+};
+
+struct st_action_data {
+        u64     when;
+        u8      action;
+        u8      __unused[7];
+};
+
+struct st_sys_release_data {
+        u64     when;
+        u64     release;
+};
+
+#define DATA(x) struct st_ ## x ## _data x;
+
+typedef enum {
+        ST_NAME = 1,            /* Start at one, so that we can spot
+                                 * uninitialized records. */
+        ST_PARAM,
+        ST_RELEASE,
+        ST_ASSIGNED,
+        ST_SWITCH_TO,
+        ST_SWITCH_AWAY,
+        ST_COMPLETION,
+        ST_BLOCK,
+        ST_RESUME,
+        ST_ACTION,
+        ST_SYS_RELEASE
+} st_event_record_type_t;
+
+struct st_event_record {
+        struct st_trace_header hdr;
+        union {
+                u64 raw[2];
+
+                DATA(name);
+                DATA(param);
+                DATA(release);
+                DATA(assigned);
+                DATA(switch_to);
+                DATA(switch_away);
+                DATA(completion);
+                DATA(block);
+                DATA(resume);
+                DATA(action);
+                DATA(sys_release);
+        } data;
+};
+
+#undef DATA
+
+#ifdef __KERNEL__
+
+#include <linux/sched.h>
+#include <litmus/feather_trace.h>
+
+#ifdef CONFIG_SCHED_TASK_TRACE
+
+#define SCHED_TRACE(id, callback, task) \
+        ft_event1(id, callback, task)
+#define SCHED_TRACE2(id, callback, task, xtra) \
+        ft_event2(id, callback, task, xtra)
+
+/* provide prototypes; needed on sparc64 */
+#ifndef NO_TASK_TRACE_DECLS
+feather_callback void do_sched_trace_task_name(unsigned long id,
+                                               struct task_struct* task);
+feather_callback void do_sched_trace_task_param(unsigned long id,
+                                                struct task_struct* task);
+feather_callback void do_sched_trace_task_release(unsigned long id,
+                                                  struct task_struct* task);
+feather_callback void do_sched_trace_task_switch_to(unsigned long id,
+                                                    struct task_struct* task);
+feather_callback void do_sched_trace_task_switch_away(unsigned long id,
+                                                      struct task_struct* task);
+feather_callback void do_sched_trace_task_completion(unsigned long id,
+                                                     struct task_struct* task,
+                                                     unsigned long forced);
+feather_callback void do_sched_trace_task_block(unsigned long id,
+                                                struct task_struct* task);
+feather_callback void do_sched_trace_task_resume(unsigned long id,
+                                                 struct task_struct* task);
+feather_callback void do_sched_trace_action(unsigned long id,
+                                            struct task_struct* task,
+                                            unsigned long action);
+feather_callback void do_sched_trace_sys_release(unsigned long id,
+                                                 lt_t* start);
+
+#endif
+
+#else
+
+#define SCHED_TRACE(id, callback, task)        /* no tracing */
+#define SCHED_TRACE2(id, callback, task, xtra) /* no tracing */
+
+#endif
+
+
+#define SCHED_TRACE_BASE_ID 500
+
+
+#define sched_trace_task_name(t) \
+        SCHED_TRACE(SCHED_TRACE_BASE_ID + 1, do_sched_trace_task_name, t)
+#define sched_trace_task_param(t) \
+        SCHED_TRACE(SCHED_TRACE_BASE_ID + 2, do_sched_trace_task_param, t)
+#define sched_trace_task_release(t) \
+        SCHED_TRACE(SCHED_TRACE_BASE_ID + 3, do_sched_trace_task_release, t)
+#define sched_trace_task_switch_to(t) \
+        SCHED_TRACE(SCHED_TRACE_BASE_ID + 4, do_sched_trace_task_switch_to, t)
+#define sched_trace_task_switch_away(t) \
+        SCHED_TRACE(SCHED_TRACE_BASE_ID + 5, do_sched_trace_task_switch_away, t)
+#define sched_trace_task_completion(t, forced) \
+        SCHED_TRACE2(SCHED_TRACE_BASE_ID + 6, do_sched_trace_task_completion, t, \
+                     (unsigned long) forced)
+#define sched_trace_task_block(t) \
+        SCHED_TRACE(SCHED_TRACE_BASE_ID + 7, do_sched_trace_task_block, t)
+#define sched_trace_task_resume(t) \
+        SCHED_TRACE(SCHED_TRACE_BASE_ID + 8, do_sched_trace_task_resume, t)
+#define sched_trace_action(t, action) \
+        SCHED_TRACE2(SCHED_TRACE_BASE_ID + 9, do_sched_trace_action, t, \
+                     (unsigned long) action);
+/* when is a pointer, it does not need an explicit cast to unsigned long */
+#define sched_trace_sys_release(when) \
+        SCHED_TRACE(SCHED_TRACE_BASE_ID + 10, do_sched_trace_sys_release, when)
+
+
+#define sched_trace_quantum_boundary() /* NOT IMPLEMENTED */
+
+#endif /* __KERNEL__ */
+
+#endif
diff --git a/include/litmus/srp.h b/include/litmus/srp.h
new file mode 100644
index 000000000000..c9a4552b2bf3
--- /dev/null
+++ b/include/litmus/srp.h
@@ -0,0 +1,28 @@
+#ifndef LITMUS_SRP_H
+#define LITMUS_SRP_H
+
+struct srp_semaphore;
+
+struct srp_priority {
+        struct list_head        list;
+        unsigned int            priority;
+        pid_t                   pid;
+};
+#define list2prio(l) list_entry(l, struct srp_priority, list)
+
+/* struct for uniprocessor SRP "semaphore" */
+struct srp_semaphore {
+        struct litmus_lock litmus_lock;
+        struct srp_priority ceiling;
+        struct task_struct* owner;
+        int cpu; /* cpu associated with this "semaphore" and resource */
+};
+
+/* map a task to its SRP preemption level priority */
+typedef unsigned int (*srp_prioritization_t)(struct task_struct* t);
+/* Must be updated by each plugin that uses SRP.*/
+extern srp_prioritization_t get_srp_prio;
+
+struct srp_semaphore* allocate_srp_semaphore(void);
+
+#endif
diff --git a/include/litmus/trace.h b/include/litmus/trace.h
new file mode 100644
index 000000000000..d6829c416912
--- /dev/null
+++ b/include/litmus/trace.h
@@ -0,0 +1,129 @@
+#ifndef _SYS_TRACE_H_
+#define _SYS_TRACE_H_
+
+#ifdef CONFIG_SCHED_OVERHEAD_TRACE
+
+#include <litmus/feather_trace.h>
+#include <litmus/feather_buffer.h>
+
+
+/*********************** TIMESTAMPS ************************/
+
+enum task_type_marker {
+        TSK_BE,
+        TSK_RT,
+        TSK_UNKNOWN
+};
+
+struct timestamp {
+        uint64_t                timestamp;
+        uint32_t                seq_no;
+        uint8_t                 cpu;
+        uint8_t                 event;
+        uint8_t                 task_type;
+};
+
+/* tracing callbacks */
+feather_callback void save_timestamp(unsigned long event);
+feather_callback void save_timestamp_def(unsigned long event, unsigned long type);
+feather_callback void save_timestamp_task(unsigned long event, unsigned long t_ptr);
+feather_callback void save_timestamp_cpu(unsigned long event, unsigned long cpu);
+feather_callback void save_task_latency(unsigned long event, unsigned long when_ptr);
+feather_callback void save_timestamp_time(unsigned long event, unsigned long time_ptr);
+
+#define TIMESTAMP(id) ft_event0(id, save_timestamp)
+
+#define DTIMESTAMP(id, def)  ft_event1(id, save_timestamp_def, (unsigned long) def)
+
+#define TTIMESTAMP(id, task) \
+        ft_event1(id, save_timestamp_task, (unsigned long) task)
+
+#define CTIMESTAMP(id, cpu) \
+        ft_event1(id, save_timestamp_cpu, (unsigned long) cpu)
+
+#define LTIMESTAMP(id, task) \
+        ft_event1(id, save_task_latency, (unsigned long) task)
+
+#define TIMESTAMP_TIME(id, time_ptr) \
+        ft_event1(id, save_timestamp_time, (unsigned long) time_ptr)
+
+#define TIMESTAMP_PID(id) ft_event0(id, save_timestamp_pid)
+
+#else /* !CONFIG_SCHED_OVERHEAD_TRACE */
+
+#define TIMESTAMP(id)        /* no tracing */
+
+#define DTIMESTAMP(id, def)  /* no tracing */
+
+#define TTIMESTAMP(id, task) /* no tracing */
+
+#define CTIMESTAMP(id, cpu)  /* no tracing */
+
+#define LTIMESTAMP(id, when_ptr) /* no tracing */
+
+#define TIMESTAMP_TIME(id, time_ptr) /* no tracing */
+
+#define TIMESTAMP_PID(id) /* no tracing */
+
+#endif
+
+
+/* Convention for timestamps
+ * =========================
+ *
+ * In order to process the trace files with a common tool, we use the following
+ * convention to measure execution times: The end time id of a code segment is
+ * always the next number after the start time event id.
+ */
+
+#define __TS_SYSCALL_IN_START(p)        TIMESTAMP_TIME(10, p)
+#define TS_SYSCALL_IN_END               TIMESTAMP_PID(11)
+
+#define TS_SYSCALL_OUT_START            TIMESTAMP_PID(20)
+#define TS_SYSCALL_OUT_END              TIMESTAMP_PID(21)
+
+#define TS_LOCK_START                   TIMESTAMP_PID(30)
+#define TS_LOCK_END                     TIMESTAMP_PID(31)
+
+#define TS_LOCK_SUSPEND                 TIMESTAMP_PID(38)
+#define TS_LOCK_RESUME                  TIMESTAMP_PID(39)
+
+#define TS_UNLOCK_START                 TIMESTAMP_PID(40)
+#define TS_UNLOCK_END                   TIMESTAMP_PID(41)
+
+#define TS_SCHED_START                  DTIMESTAMP(100, TSK_UNKNOWN) /* we only
+                                                                      * care
+                                                                      * about
+                                                                      * next */
+#define TS_SCHED_END(t)                 TTIMESTAMP(101, t)
+#define TS_SCHED2_START(t)              TTIMESTAMP(102, t)
+#define TS_SCHED2_END(t)                TTIMESTAMP(103, t)
+
+#define TS_CXS_START(t)                 TTIMESTAMP(104, t)
+#define TS_CXS_END(t)                   TTIMESTAMP(105, t)
+
+#define TS_RELEASE_START                DTIMESTAMP(106, TSK_RT)
+#define TS_RELEASE_END                  DTIMESTAMP(107, TSK_RT)
+
+#define TS_TICK_START(t)                TTIMESTAMP(110, t)
+#define TS_TICK_END(t)                  TTIMESTAMP(111, t)
+
+
+#define TS_PLUGIN_SCHED_START           /* TIMESTAMP(120) */  /* currently unused */
+#define TS_PLUGIN_SCHED_END             /* TIMESTAMP(121) */
+
+#define TS_PLUGIN_TICK_START            /* TIMESTAMP(130) */
+#define TS_PLUGIN_TICK_END              /* TIMESTAMP(131) */
+
+#define TS_ENTER_NP_START               TIMESTAMP(140)
+#define TS_ENTER_NP_END                 TIMESTAMP(141)
+
+#define TS_EXIT_NP_START                TIMESTAMP(150)
+#define TS_EXIT_NP_END                  TIMESTAMP(151)
+
+#define TS_SEND_RESCHED_START(c)        CTIMESTAMP(190, c)
+#define TS_SEND_RESCHED_END             DTIMESTAMP(191, TSK_UNKNOWN)
+
+#define TS_RELEASE_LATENCY(when)        LTIMESTAMP(208, &(when))
+
+#endif /* !_SYS_TRACE_H_ */
diff --git a/include/litmus/unistd_32.h b/include/litmus/unistd_32.h
new file mode 100644
index 000000000000..94264c27d9ac
--- /dev/null
+++ b/include/litmus/unistd_32.h
@@ -0,0 +1,21 @@
+/*
+ * included from arch/x86/include/asm/unistd_32.h
+ *
+ * LITMUS^RT syscalls with "relative" numbers
+ */
+#define __LSC(x) (__NR_LITMUS + x)
+
+#define __NR_set_rt_task_param  __LSC(0)
+#define __NR_get_rt_task_param  __LSC(1)
+#define __NR_complete_job       __LSC(2)
+#define __NR_od_open            __LSC(3)
+#define __NR_od_close           __LSC(4)
+#define __NR_litmus_lock        __LSC(5)
+#define __NR_litmus_unlock      __LSC(6)
+#define __NR_query_job_no       __LSC(7)
+#define __NR_wait_for_job_release __LSC(8)
+#define __NR_wait_for_ts_release __LSC(9)
+#define __NR_release_ts         __LSC(10)
+#define __NR_null_call          __LSC(11)
+
+#define NR_litmus_syscalls 12
diff --git a/include/litmus/unistd_64.h b/include/litmus/unistd_64.h
new file mode 100644
index 000000000000..d5ced0d2642c
--- /dev/null
+++ b/include/litmus/unistd_64.h
@@ -0,0 +1,33 @@
+/*
+ * included from arch/x86/include/asm/unistd_64.h
+ *
+ * LITMUS^RT syscalls with "relative" numbers
+ */
+#define __LSC(x) (__NR_LITMUS + x)
+
+#define __NR_set_rt_task_param                  __LSC(0)
+__SYSCALL(__NR_set_rt_task_param, sys_set_rt_task_param)
+#define __NR_get_rt_task_param                  __LSC(1)
+__SYSCALL(__NR_get_rt_task_param, sys_get_rt_task_param)
+#define __NR_complete_job                       __LSC(2)
+__SYSCALL(__NR_complete_job, sys_complete_job)
+#define __NR_od_open                            __LSC(3)
+__SYSCALL(__NR_od_open, sys_od_open)
+#define __NR_od_close                           __LSC(4)
+__SYSCALL(__NR_od_close, sys_od_close)
+#define __NR_litmus_lock                        __LSC(5)
+__SYSCALL(__NR_litmus_lock, sys_litmus_lock)
+#define __NR_litmus_unlock                      __LSC(6)
+__SYSCALL(__NR_litmus_unlock, sys_litmus_unlock)
+#define __NR_query_job_no                       __LSC(7)
+__SYSCALL(__NR_query_job_no, sys_query_job_no)
+#define __NR_wait_for_job_release               __LSC(8)
+__SYSCALL(__NR_wait_for_job_release, sys_wait_for_job_release)
+#define __NR_wait_for_ts_release                __LSC(9)
+__SYSCALL(__NR_wait_for_ts_release, sys_wait_for_ts_release)
+#define __NR_release_ts                         __LSC(10)
+__SYSCALL(__NR_release_ts, sys_release_ts)
+#define __NR_null_call                          __LSC(11)
+__SYSCALL(__NR_null_call, sys_null_call)
+
+#define NR_litmus_syscalls 12
diff --git a/include/litmus/wait.h b/include/litmus/wait.h
new file mode 100644
index 000000000000..ce1347c355f8
--- /dev/null
+++ b/include/litmus/wait.h
@@ -0,0 +1,57 @@
+#ifndef _LITMUS_WAIT_H_
+#define _LITMUS_WAIT_H_
+
+struct task_struct* __waitqueue_remove_first(wait_queue_head_t *wq);
+
+/* wrap regular wait_queue_t head */
+struct __prio_wait_queue {
+        wait_queue_t wq;
+
+        /* some priority point */
+        lt_t priority;
+        /* break ties in priority by lower tie_breaker */
+        unsigned int tie_breaker;
+};
+
+typedef struct __prio_wait_queue prio_wait_queue_t;
+
+static inline void init_prio_waitqueue_entry(prio_wait_queue_t *pwq,
+                                             struct task_struct* t,
+                                             lt_t priority)
+{
+        init_waitqueue_entry(&pwq->wq, t);
+        pwq->priority    = priority;
+        pwq->tie_breaker = 0;
+}
+
+static inline void init_prio_waitqueue_entry_tie(prio_wait_queue_t *pwq,
+                                                 struct task_struct* t,
+                                                 lt_t priority,
+                                                 unsigned int tie_breaker)
+{
+        init_waitqueue_entry(&pwq->wq, t);
+        pwq->priority    = priority;
+        pwq->tie_breaker = tie_breaker;
+}
+
+unsigned int __add_wait_queue_prio_exclusive(
+        wait_queue_head_t* head,
+        prio_wait_queue_t *new);
+
+static inline unsigned int add_wait_queue_prio_exclusive(
+        wait_queue_head_t* head,
+        prio_wait_queue_t *new)
+{
+        unsigned long flags;
+        unsigned int passed;
+
+        spin_lock_irqsave(&head->lock, flags);
+        passed = __add_wait_queue_prio_exclusive(head, new);
+
+        spin_unlock_irqrestore(&head->lock, flags);
+
+        return passed;
+}
+
+
+#endif