feature: added SJF scheduler

added REGRESSION based prediction support

Author: emil916

.vscode/settings.json

@@ -116,7 +116,7 @@
 		"tenant.h": "c",
 		"route_config.h": "c",
 		"http_router.h": "c",
-		"admissions_info.h": "c",
+		"execution_histogram.h": "c",
 		"tcp_server.h": "c",
 		"stdint.h": "c",
 		"scheduler_options.h": "c",
@@ -144,7 +144,20 @@
 		"algorithm": "c",
 		"stdio.h": "c",
 		"get_time.h": "c",
-		"unistd.h": "c"
+		"unistd.h": "c",
+		"wasi.h": "c",
+		"stat.h": "c",
+		"functional": "c",
+		"sandbox_state.h": "c",
+		"ratio": "c",
+		"tuple": "c",
+		"type_traits": "c",
+		"perf_window.h": "c",
+		"http_route_total.h": "c",
+		"sledge_abi_symbols.h": "c",
+		"mutex": "c",
+		"lock.h": "c",
+		"route_latency.h": "c"
 	},
 	"files.exclude": {
 		"**/.git": true,

applications/Makefile

@@ -27,6 +27,7 @@ all: \
 	license_plate_detection.install \
 	resize_image.install \
 	cnn_face_detection.install \
+	get_jpeg_resolution.install \
 	scratch_storage_get.install \
 	scratch_storage_set.install \
 	scratch_storage_delete.install \
@@ -109,6 +110,9 @@ license_plate_detection.install: ../runtime/bin/license_plate_detection.wasm.so
 .PHONY: cnn_face_detection.install
 cnn_face_detection.install: ../runtime/bin/cnn_face_detection.wasm.so
 
+.PHONY: get_jpeg_resolution.install
+get_jpeg_resolution.install: ../runtime/bin/get_jpeg_resolution.wasm.so
+
 .PHONY: trap_divzero.install
 trap_divzero.install: ../runtime/bin/trap_divzero.wasm.so
 

awsm

@@ -38,6 +38,10 @@ BINARY_NAME=sledgert
 
 
 # Feature Toggles
+CFLAGS += -DEXECUTION_HISTOGRAM
+# CFLAGS += -DEXECUTION_REGRESSION
+
+# It is recommended (not mandatory) to enable this flag along with the EXECUTION_HISTOGRAM flag:
 # CFLAGS += -DADMISSIONS_CONTROL
 
 # Debugging Flags
@@ -56,6 +60,7 @@ BINARY_NAME=sledgert
 # CFLAGS += -DLOG_TO_FILE
 
 # Various Informational Logs for Debugging
+# CFLAGS += -DLOG_EXECUTION_HISTOGRAM
 # CFLAGS += -DLOG_ADMISSIONS_CONTROL
 # CFLAGS += -DLOG_CONTEXT_SWITCHES
 # CFLAGS += -DLOG_HTTP_PARSER

runtime/Makefile

@@ -1,18 +1,19 @@
 #pragma once
 
+#ifdef ADMISSIONS_CONTROL
+
 #include <stdbool.h>
 #include <stdint.h>
 
-#ifdef ADMISSIONS_CONTROL
 #define ADMISSIONS_CONTROL_GRANULARITY 1000000
 extern _Atomic uint64_t admissions_control_admitted;
 extern uint64_t         admissions_control_capacity;
-#endif
 
 void     admissions_control_initialize(void);
 void     admissions_control_add(uint64_t admissions_estimate);
 void     admissions_control_subtract(uint64_t admissions_estimate);
 uint64_t admissions_control_calculate_estimate(uint64_t estimated_execution, uint64_t relative_deadline);
-uint64_t admissions_control_calculate_estimate_us(uint32_t estimated_execution_us, uint32_t relative_deadline_us);
 void     admissions_control_log_decision(uint64_t admissions_estimate, bool admitted);
 uint64_t admissions_control_decide(uint64_t admissions_estimate);
+
+#endif

runtime/include/admissions_control.h

@@ -4,6 +4,7 @@
 
 #include "current_wasm_module_instance.h"
 #include "sandbox_types.h"
+#include "listener_thread.h"
 
 /* current sandbox that is active.. */
 extern thread_local struct sandbox *worker_thread_current_sandbox;
@@ -46,17 +47,19 @@ current_sandbox_set(struct sandbox *sandbox)
 			/* Private */
 			.wasi_context = NULL,
 		};
-		worker_thread_current_sandbox                      = NULL;
-		runtime_worker_threads_deadline[worker_thread_idx] = UINT64_MAX;
+		worker_thread_current_sandbox = NULL;
+		/* This is because the event core does not maintain core-assigned deadline */
+		if (!listener_thread_is_running()) runtime_worker_threads_deadline[worker_thread_idx] = UINT64_MAX;
 	} else {
 		sledge_abi__current_wasm_module_instance.wasi_context = sandbox->wasi_context;
 		memcpy(&sledge_abi__current_wasm_module_instance.abi.memory, &sandbox->memory->abi,
 		       sizeof(struct sledge_abi__wasm_memory));
 		sledge_abi__current_wasm_module_instance.abi.table = sandbox->module->indirect_table;
 		wasm_globals_update_if_used(&sandbox->globals, 0,
 		                            &sledge_abi__current_wasm_module_instance.abi.wasmg_0);
-		worker_thread_current_sandbox                      = sandbox;
-		runtime_worker_threads_deadline[worker_thread_idx] = sandbox->absolute_deadline;
+		worker_thread_current_sandbox = sandbox;
+		if (!listener_thread_is_running())
+			runtime_worker_threads_deadline[worker_thread_idx] = sandbox->absolute_deadline;
 	}
 }
 

runtime/include/admissions_info.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include "perf_window_t.h"
+
+struct execution_histogram {
+	struct perf_window perf_window;
+	uint8_t            percentile;          /* 50 - 99 */
+	int                control_index;       /* Precomputed Lookup index when perf_window is full */
+	uint64_t           estimated_execution; /* cycles */
+};
+
+void execution_histogram_initialize(struct execution_histogram *execution_histogram, uint8_t percentile,
+                                    uint64_t expected_execution);
+void execution_histogram_update(struct execution_histogram *execution_histogram, uint64_t execution_duration);

runtime/include/current_sandbox.h

@@ -0,0 +1,25 @@
+#pragma once
+
+#ifdef EXECUTION_REGRESSION
+
+#include <stdint.h>
+#include "http_session.h"
+
+static inline uint64_t
+get_regression_prediction(struct http_session *session)
+{
+	/* Default Pre-processing - Extract payload size */
+	const int payload_size = session->http_request.body_length;
+
+	const double regression_params[2] = { payload_size, session->param2 };
+
+	/* Regression */
+	const struct regression_model model      = session->route->regr_model;
+	const uint64_t                prediction = (regression_params[0] / model.scale * model.beta1
+                                     + regression_params[1] / model.scale * model.beta2)
+	                            + model.bias;
+
+	return prediction;
+}
+
+#endif

runtime/include/execution_histogram.h

@@ -1,8 +1,6 @@
 #pragma once
 
 #include <stdlib.h>
-#include <string.h>
-
 #include "http.h"
 #include "module.h"
 #include "route_latency.h"
@@ -22,7 +20,8 @@ http_router_init(http_router_t *router, size_t capacity)
 }
 
 static inline int
-http_router_add_route(http_router_t *router, struct route_config *config, struct module *module)
+http_router_add_route(http_router_t *router, struct route_config *config, struct module *module,
+                      struct module *pre_module)
 {
 	assert(router != NULL);
 	assert(config != NULL);
@@ -40,10 +39,27 @@ http_router_add_route(http_router_t *router, struct route_config *config, struct
 	route_latency_init(&route.latency);
 	http_route_total_init(&route.metrics);
 
-	/* Admissions Control */
-	uint64_t expected_execution = (uint64_t)config->expected_execution_us * runtime_processor_speed_MHz;
-	admissions_info_initialize(&route.admissions_info, config->admissions_percentile, expected_execution,
-	                           route.relative_deadline);
+#ifdef EXECUTION_REGRESSION
+	/* Execution Regression setup */
+	assert(pre_module);
+	route.pre_module              = pre_module;
+	route.regr_model.bias         = config->model_bias / 1000.0;
+	route.regr_model.scale        = config->model_scale / 1000.0;
+	route.regr_model.num_of_param = config->model_num_of_param;
+	route.regr_model.beta1        = config->model_beta1 / 1000.0;
+	route.regr_model.beta2        = config->model_beta2 / 1000.0;
+#endif
+
+	const uint64_t expected_execution = route.relative_deadline / 2;
+#ifdef ADMISSIONS_CONTROL
+	/* Addmissions Control setup */
+	route.execution_histogram.estimated_execution = expected_execution;
+#endif
+
+#ifdef EXECUTION_HISTOGRAM
+	/* Execution Histogram setup */
+	execution_histogram_initialize(&route.execution_histogram, config->admissions_percentile, expected_execution);
+#endif
 
 	int rc = vec_route_t_push(router, route);
 	if (unlikely(rc == -1)) { return -1; }

runtime/include/execution_regression.h

@@ -57,6 +57,9 @@ struct http_session {
 	uint64_t                request_downloaded_timestamp;
 	uint64_t                response_takeoff_timestamp;
 	uint64_t                response_sent_timestamp;
+	bool                    did_preprocessing;
+	uint64_t                preprocessing_duration;
+	double                  param2;
 };
 
 extern void http_session_perf_log_print_entry(struct http_session *http_session);

runtime/include/http_router.h

@@ -15,8 +15,8 @@ static inline void
 http_session_perf_log_print_header()
 {
 	if (http_session_perf_log == NULL) { perror("http_session perf log"); }
-	fprintf(http_session_perf_log,
-	        "tenant,route,state,header_len,resp_body_len,receive_duration,sent_duration,total_lifetime,proc_MHz\n");
+	fprintf(http_session_perf_log, "tenant,route,state,header_len,resp_body_len,receive_duration,sent_duration,"
+	                               "total_lifetime,preprocessing,proc_MHz\n");
 }
 
 static inline void

runtime/include/http_session.h

@@ -1,22 +1,11 @@
 #pragma once
 
-#include <string.h>
-#include <sys/socket.h>
-#include <sys/types.h>
-#include <netdb.h>
-
-#include "admissions_control.h"
-#include "admissions_info.h"
 #include "current_wasm_module_instance.h"
-#include "panic.h"
 #include "pool.h"
-#include "sledge_abi_symbols.h"
-#include "tcp_server.h"
 #include "types.h"
 #include "sledge_abi_symbols.h"
 #include "wasm_stack.h"
 #include "wasm_memory.h"
-#include "wasm_table.h"
 
 extern thread_local int worker_thread_idx;
 
@@ -28,9 +17,15 @@ struct module_pool {
 	struct wasm_stack_pool  stack;
 } CACHE_PAD_ALIGNED;
 
+enum module_type
+{
+	APP_MODULE,
+	PREPROCESS_MODULE
+};
 struct module {
-	char    *path;
-	uint32_t stack_size; /* a specification? */
+	char            *path;
+	uint32_t         stack_size; /* a specification? */
+	enum module_type type;
 
 	/* Handle and ABI Symbols for *.so file */
 	struct sledge_abi_symbols abi;
@@ -41,12 +36,13 @@ struct module {
 	struct module_pool *pools;
 } CACHE_PAD_ALIGNED;
 
+
 /********************************
  * Public Methods from module.c *
  *******************************/
 
 void           module_free(struct module *module);
-struct module *module_alloc(char *path);
+struct module *module_alloc(char *path, enum module_type type);
 
 /*************************
  * Public Static Inlines *
@@ -115,7 +111,8 @@ module_alloc_table(struct module *module)
 static inline void
 module_initialize_pools(struct module *module)
 {
-	for (int i = 0; i < runtime_worker_threads_count; i++) {
+	/* Create only a single pool for the preprocessing module, since it is executed only by the event core. */
+	for (int i = 0; i < (module->type == APP_MODULE ? runtime_worker_threads_count : 1); i++) {
 		wasm_memory_pool_init(&module->pools[i].memory, false);
 		wasm_stack_pool_init(&module->pools[i].stack, false);
 	}
@@ -124,7 +121,7 @@ module_initialize_pools(struct module *module)
 static inline void
 module_deinitialize_pools(struct module *module)
 {
-	for (int i = 0; i < runtime_worker_threads_count; i++) {
+	for (int i = 0; i < (module->type == APP_MODULE ? runtime_worker_threads_count : 1); i++) {
 		wasm_memory_pool_deinit(&module->pools[i].memory);
 		wasm_stack_pool_deinit(&module->pools[i].stack);
 	}

runtime/include/http_session_perf_log.h

@@ -3,20 +3,30 @@
 #include <stdint.h>
 #include <stddef.h>
 
-#include "admissions_info.h"
+#include "execution_histogram.h"
 #include "module.h"
 #include "http_route_total.h"
 #include "perf_window.h"
 
+struct regression_model {
+	double   bias;
+	double   scale;
+	uint32_t num_of_param;
+	double   beta1;
+	double   beta2;
+};
+
 /* Assumption: entrypoint is always _start. This should be enhanced later */
 struct route {
 	char                   *route;
 	struct http_route_total metrics;
 	struct module          *module;
+	struct module          *pre_module;
 	/* HTTP State */
-	uint32_t               relative_deadline_us;
-	uint64_t               relative_deadline; /* cycles */
-	char                  *response_content_type;
-	struct admissions_info admissions_info;
-	struct perf_window     latency;
+	uint32_t                   relative_deadline_us;
+	uint64_t                   relative_deadline; /* cycles */
+	char                      *response_content_type;
+	struct execution_histogram execution_histogram;
+	struct perf_window         latency;
+	struct regression_model    regr_model;
 };