Add schedule tracing support

This patch introduces the sched_trace infrastructure, which in
principle allows tracing the generated schedule.  However, this patch
does not yet integrate the callbacks with the kernel.

1 files changed, 251 insertions, 0 deletions

diff --git a/include/litmus/sched_trace.h b/include/litmus/sched_trace.h
new file mode 100644
index 000000000000..6044d9f0a05a
--- /dev/null
+++ b/include/litmus/sched_trace.h
@@ -0,0 +1,251 @@
+/*
+ * 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
+
+#ifdef CONFIG_SCHED_LITMUS_TRACEPOINT
+
+#include <trace/events/litmus.h>
+
+#else
+
+/* Override trace macros to actually do nothing */
+#define trace_litmus_task_param(t)
+#define trace_litmus_task_release(t)
+#define trace_litmus_switch_to(t)
+#define trace_litmus_switch_away(prev)
+#define trace_litmus_task_completion(t, forced)
+#define trace_litmus_task_block(t)
+#define trace_litmus_task_resume(t)
+#define trace_litmus_sys_release(start)
+
+#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)                                       \
+        do {                                                            \
+                SCHED_TRACE(SCHED_TRACE_BASE_ID + 2,                    \
+                                do_sched_trace_task_param, t);          \
+        } while (0)
+
+#define sched_trace_task_release(t)                                     \
+        do {                                                            \
+                SCHED_TRACE(SCHED_TRACE_BASE_ID + 3,                    \
+                                do_sched_trace_task_release, t);        \
+        } while (0)
+
+#define sched_trace_task_switch_to(t)                                   \
+        do {                                                            \
+                SCHED_TRACE(SCHED_TRACE_BASE_ID + 4,                    \
+                        do_sched_trace_task_switch_to, t);              \
+        } while (0)
+
+#define sched_trace_task_switch_away(t)                                 \
+        do {                                                            \
+                SCHED_TRACE(SCHED_TRACE_BASE_ID + 5,                    \
+                        do_sched_trace_task_switch_away, t);            \
+        } while (0)
+
+#define sched_trace_task_completion(t, forced)                          \
+        do {                                                            \
+                SCHED_TRACE2(SCHED_TRACE_BASE_ID + 6,                   \
+                                do_sched_trace_task_completion, t,      \
+                                (unsigned long) forced);                \
+        } while (0)
+
+#define sched_trace_task_block(t)                                       \
+        do {                                                            \
+                SCHED_TRACE(SCHED_TRACE_BASE_ID + 7,                    \
+                        do_sched_trace_task_block, t);                  \
+        } while (0)
+
+#define sched_trace_task_resume(t)                                      \
+        do {                                                            \
+                SCHED_TRACE(SCHED_TRACE_BASE_ID + 8,                    \
+                                do_sched_trace_task_resume, t);         \
+        } while (0)
+
+#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)                                   \
+        do {                                                            \
+                SCHED_TRACE(SCHED_TRACE_BASE_ID + 10,                   \
+                        do_sched_trace_sys_release, when);              \
+        } while (0)
+
+#define sched_trace_quantum_boundary() /* NOT IMPLEMENTED */
+
+#endif /* __KERNEL__ */
+
+#endif