kernel: Swap RUNTIME_STATS implementation

Clean up RUNTIME_STATS to separate the API from the individual data
backends.  Use the SCHED_THREAD_USAGE tracking instead of the original
for execution_cycles.  Move the kconfig for that into the runtime
stats menu, since it's part of the family now.

Also remove a lot of needless #if's around the declarations.  Unused
structs and uncalled functions don't need to be explicitly hidden.  An
attempt to access a non-existent field (e.g. "execution_cycles" if
that isn't configured) provides all the build time validation we need.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>

include/kernel.h

@@ -21,10 +21,6 @@
 #include <toolchain.h>
 #include <tracing/tracing_macros.h>
 
-#ifdef CONFIG_THREAD_RUNTIME_STATS_USE_TIMING_FUNCTIONS
-#include <timing/timing.h>
-#endif
-
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -5874,8 +5870,6 @@ __syscall int k_float_disable(struct k_thread *thread);
  */
 __syscall int k_float_enable(struct k_thread *thread, unsigned int options);
 
-#ifdef CONFIG_THREAD_RUNTIME_STATS
-
 /**
  * @brief Get the runtime statistics of a thread
  *
@@ -5894,8 +5888,6 @@ int k_thread_runtime_stats_get(k_tid_t thread,
  */
 int k_thread_runtime_stats_all_get(k_thread_runtime_stats_t *stats);
 
-#endif
-
 #ifdef __cplusplus
 }
 #endif

include/kernel/thread.h

@@ -169,29 +169,11 @@ struct _thread_userspace_local_data {
 };
 #endif
 
-#ifdef CONFIG_THREAD_RUNTIME_STATS
+typedef struct k_thread_runtime_stats {
-struct k_thread_runtime_stats {
+#ifdef CONFIG_SCHED_THREAD_USAGE
-	/* Thread execution cycles */
-#ifdef CONFIG_THREAD_RUNTIME_STATS_USE_TIMING_FUNCTIONS
-	timing_t execution_cycles;
-#else
 	uint64_t execution_cycles;
 #endif
-};
+}  k_thread_runtime_stats_t;
-
-typedef struct k_thread_runtime_stats k_thread_runtime_stats_t;
-
-struct _thread_runtime_stats {
-	/* Timestamp when last switched in */
-#ifdef CONFIG_THREAD_RUNTIME_STATS_USE_TIMING_FUNCTIONS
-	timing_t last_switched_in;
-#else
-	uint32_t last_switched_in;
-#endif
-
-	k_thread_runtime_stats_t stats;
-};
-#endif
 
 struct z_poller {
 	bool is_polling;
@@ -289,11 +271,6 @@ struct k_thread {
 	uintptr_t tls;
 #endif /* CONFIG_THREAD_LOCAL_STORAGE */
 
-#ifdef CONFIG_THREAD_RUNTIME_STATS
-	/** Runtime statistics */
-	struct _thread_runtime_stats rt_stats;
-#endif
-
 #ifdef CONFIG_DEMAND_PAGING_THREAD_STATS
 	/** Paging statistics */
 	struct k_mem_paging_stats_t paging_stats;

kernel/Kconfig

@@ -377,26 +377,14 @@ config THREAD_MAX_NAME_LEN
 config INSTRUMENT_THREAD_SWITCHING
 	bool
 
-config SCHED_THREAD_USAGE
-	bool "Collect thread runtime usage"
-	select INSTRUMENT_THREAD_SWITCHING if !USE_SWITCH
-	help
-	  Alternate implementation of thread runtime cycle usage
-
-config SCHED_THREAD_USAGE_ALL
-	bool "Collect total system runtime usage"
-	default y if SCHED_THREAD_USAGE
-	help
-	  Maintain a sum of all non-idle thread cycle usage.
-
 menuconfig THREAD_RUNTIME_STATS
 	bool "Thread runtime statistics"
-	select INSTRUMENT_THREAD_SWITCHING
 	help
 	  Gather thread runtime statistics.
 
 	  For example:
 	    - Thread total execution cycles
+	    - System total execution cycles
 
 if THREAD_RUNTIME_STATS
 
@@ -409,6 +397,20 @@ config THREAD_RUNTIME_STATS_USE_TIMING_FUNCTIONS
 	  Note that timing functions may use a different timer than
 	  the default timer for OS timekeeping.
 
+config SCHED_THREAD_USAGE
+	bool "Collect thread runtime usage"
+	default y
+	select INSTRUMENT_THREAD_SWITCHING if !USE_SWITCH
+	help
+	  Collect thread runtime info at context switch time
+
+config SCHED_THREAD_USAGE_ALL
+	bool "Collect total system runtime usage"
+	default y if SCHED_THREAD_USAGE
+	depends on SCHED_THREAD_USAGE
+	help
+	  Maintain a sum of all non-idle thread cycle usage.
+
 endif # THREAD_RUNTIME_STATS
 
 endmenu

kernel/include/ksched.h

@@ -385,6 +385,8 @@ void z_sched_usage_stop(void);
 
 void z_sched_usage_start(struct k_thread *thread);
 
+uint64_t z_sched_thread_usage(struct k_thread *thread);
+
 static inline void z_sched_usage_switch(struct k_thread *thread)
 {
 	ARG_UNUSED(thread);

kernel/thread.c

@@ -31,10 +31,6 @@
 #include <logging/log.h>
 LOG_MODULE_DECLARE(os, CONFIG_KERNEL_LOG_LEVEL);
 
-#ifdef CONFIG_THREAD_RUNTIME_STATS
-k_thread_runtime_stats_t threads_runtime_stats;
-#endif
-
 #ifdef CONFIG_THREAD_MONITOR
 /* This lock protects the linked list of active threads; i.e. the
  * initial _kernel.threads pointer and the linked list made up of
@@ -607,10 +603,6 @@ char *z_setup_new_thread(struct k_thread *new_thread,
 
 	SYS_PORT_TRACING_OBJ_FUNC(k_thread, create, new_thread);
 
-#ifdef CONFIG_THREAD_RUNTIME_STATS
-	memset(&new_thread->rt_stats, 0, sizeof(new_thread->rt_stats));
-#endif
-
 	return stack_ptr;
 }
 
@@ -1013,18 +1005,6 @@ void z_thread_mark_switched_in(void)
 #ifdef CONFIG_TRACING
 	SYS_PORT_TRACING_FUNC(k_thread, switched_in);
 #endif
-
-#ifdef CONFIG_THREAD_RUNTIME_STATS
-	struct k_thread *thread;
-
-	thread = k_current_get();
-#ifdef CONFIG_THREAD_RUNTIME_STATS_USE_TIMING_FUNCTIONS
-	thread->rt_stats.last_switched_in = timing_counter_get();
-#else
-	thread->rt_stats.last_switched_in = k_cycle_get_32();
-#endif /* CONFIG_THREAD_RUNTIME_STATS_USE_TIMING_FUNCTIONS */
-
-#endif /* CONFIG_THREAD_RUNTIME_STATS */
 }
 
 void z_thread_mark_switched_out(void)
@@ -1033,48 +1013,12 @@ void z_thread_mark_switched_out(void)
 	z_sched_usage_stop();
 #endif
 
-#ifdef CONFIG_THREAD_RUNTIME_STATS
-#ifdef CONFIG_THREAD_RUNTIME_STATS_USE_TIMING_FUNCTIONS
-	timing_t now;
-#else
-	uint32_t now;
-#endif /* CONFIG_THREAD_RUNTIME_STATS_USE_TIMING_FUNCTIONS */
-
-	uint64_t diff;
-	struct k_thread *thread;
-
-	thread = k_current_get();
-
-	if (unlikely(thread->rt_stats.last_switched_in == 0)) {
-		/* Has not run before */
-		return;
-	}
-
-	if (unlikely(thread->base.thread_state == _THREAD_DUMMY)) {
-		/* dummy thread has no stat struct */
-		return;
-	}
-
-#ifdef CONFIG_THREAD_RUNTIME_STATS_USE_TIMING_FUNCTIONS
-	now = timing_counter_get();
-	diff = timing_cycles_get(&thread->rt_stats.last_switched_in, &now);
-#else
-	now = k_cycle_get_32();
-	diff = (uint64_t)(now - thread->rt_stats.last_switched_in);
-	thread->rt_stats.last_switched_in = 0;
-#endif /* CONFIG_THREAD_RUNTIME_STATS_USE_TIMING_FUNCTIONS */
-
-	thread->rt_stats.stats.execution_cycles += diff;
-
-	threads_runtime_stats.execution_cycles += diff;
-#endif /* CONFIG_THREAD_RUNTIME_STATS */
-
 #ifdef CONFIG_TRACING
 	SYS_PORT_TRACING_FUNC(k_thread, switched_out);
 #endif
 }
+#endif /* CONFIG_INSTRUMENT_THREAD_SWITCHING */
 
-#ifdef CONFIG_THREAD_RUNTIME_STATS
 int k_thread_runtime_stats_get(k_tid_t thread,
 			       k_thread_runtime_stats_t *stats)
 {
@@ -1082,8 +1026,11 @@ int k_thread_runtime_stats_get(k_tid_t thread,
 		return -EINVAL;
 	}
 
-	(void)memcpy(stats, &thread->rt_stats.stats,
+	*stats = (k_thread_runtime_stats_t) {};
-		     sizeof(thread->rt_stats.stats));
+
+#ifdef CONFIG_SCHED_THREAD_USAGE
+	stats->execution_cycles = z_sched_thread_usage(thread);
+#endif
 
 	return 0;
 }
@@ -1094,11 +1041,11 @@ int k_thread_runtime_stats_all_get(k_thread_runtime_stats_t *stats)
 		return -EINVAL;
 	}
 
-	(void)memcpy(stats, &threads_runtime_stats,
+	*stats = (k_thread_runtime_stats_t) {};
-		     sizeof(threads_runtime_stats));
+
+#ifdef CONFIG_SCHED_THREAD_USAGE_ALL
+	stats->execution_cycles = _kernel.all_thread_usage;
+#endif
 
 	return 0;
 }
-#endif /* CONFIG_THREAD_RUNTIME_STATS */
-
-#endif /* CONFIG_INSTRUMENT_THREAD_SWITCHING */