Implementation of core scheduling

doc/tutorial.txt

@@ -272,6 +272,38 @@ inherit the affinity from the task level):
 	}
 }
 
+*** Core Scheduling
+
+* core_scheduling_family: Integer. If two or more tasks have the same family, they will share their Core Scheduling Cookie.
+* core_scheduling_families_count: Integer. Number of core scheduling families to be created.
+
+"core_scheduling_family" can only be specified at task level.
+"core_scheduling_families_count" is a global parameter.
+In the example below it creates 2 threads with different core scheduling cookie.
+"tasks" : {
+	"thread1" : {
+		"core_scheduling_family" : 1,
+		"phases" : {
+			"phase1" : {
+				"run" : 10,
+				"sleep" : 10
+			}
+		}
+	}
+	"thread2" : {
+		"core_scheduling_family" : 2,
+		"phases" : {
+            "phase1" : {
+                "run" : 10,
+                "sleep" : 10
+            }
+        }
+	}
+},
+"global":{
+    "core_scheduling_families_count": 2
+}
+
 *** Utilization Clamping
 
 util_min: Integer. Can be specified at task level or phase level. Sets the min

src/rt-app.c

@@ -38,6 +38,24 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #include <unistd.h>
 #include <errno.h>
 
+/* Core scheduling libraries */
+#include <ctype.h>
+#include <sys/prctl.h>
+#include <linux/version.h>
+#include <semaphore.h>
+#include <sys/ptrace.h>
+#include <linux/ptrace.h>
+
+#if LINUX_VERSION_CODE <= KERNEL_VERSION(5,16,0)
+
+typedef enum {PIDTYPE_PID,PIDTYPE_TGID,PIDTYPE_PGID,PIDTYPE_SID,PIDTYPE_MAX}pid_type;
+
+#define PR_SCHED_CORE_SCOPE_THREAD		0
+#define PR_SCHED_CORE_SCOPE_THREAD_GROUP	1
+#define PR_SCHED_CORE_SCOPE_PROCESS_GROUP	2
+
+#endif
+
 #include "config.h"
 #include "rt-app_utils.h"
 #include "rt-app_args.h"
@@ -63,6 +81,9 @@ static pthread_barrier_t threads_barrier;
 static pthread_mutex_t joining_mutex;
 static pthread_mutex_t fork_mutex;
 
+static pid_t *core_scheduling_first_threads;
+static pthread_mutex_t core_scheduling_mutex;
+
 static ftrace_data_t ft_data = {
 	.debugfs = "/sys/kernel/debug",
 	.marker_fd = -1,
@@ -736,6 +757,7 @@ static void __shutdown(bool force_terminate)
 		free(threads[i].data);
 	}
 
+    	free(core_scheduling_first_threads);
 
 	log_ftrace(ft_data.marker_fd, FTRACE_MAIN,
 		   "rtapp_main: event=end");
@@ -745,7 +767,6 @@ static void __shutdown(bool force_terminate)
 	}
 
 	remove_cgroups();
-
 	/*
 	 * If we unlock the joining_mutex here we could risk a late SIGINT
 	 * causing us to re-enter this loop. Since we are calling exit() to
@@ -1144,7 +1165,33 @@ void *thread_body(void *arg)
 		perror("pthread_setname_np thread name over 16 characters");
 	}
 
-	/* Get the 1st phase's data */
+    	/* Set core scheduling family */
+        if (data->core_scheduling_family != 0) {
+		if (opts.core_scheduling_families_count >= data->core_scheduling_family) {
+            		pthread_mutex_lock(&core_scheduling_mutex);
+            		if (core_scheduling_first_threads[data->core_scheduling_family-1] != 0) {
+                		if (prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_FROM, 
+					  core_scheduling_first_threads[data->core_scheduling_family-1], 
+					  PR_SCHED_CORE_SCOPE_THREAD, 0)) {
+                    			perror("Error copying core scheduling cookie");
+                		}
+            		} else {
+                		core_scheduling_first_threads[data->core_scheduling_family-1] = gettid();
+                		if (prctl(PR_SCHED_CORE, PR_SCHED_CORE_CREATE, 
+				    gettid(), PR_SCHED_CORE_SCOPE_THREAD, 0)) {
+                    			perror("Error creating core scheduling cookie");
+                		}
+           	 	}
+            		pthread_mutex_unlock(&core_scheduling_mutex);
+        	}
+
+        	u_long test;
+        	prctl(PR_SCHED_CORE, PR_SCHED_CORE_GET, gettid(), PR_SCHED_CORE_SCOPE_THREAD, &test);
+        	log_notice("[%d] Core scheduling cookie set to %lu, family %d", 
+			   data->ind, test, data->core_scheduling_family);
+    	}
+
+    	/* Get the 1st phase's data */
 	pdata = &data->phases[0];
 
 	/* Init timing buffer */
@@ -1507,7 +1554,7 @@ static void setup_main_gnuplot(void)
 
 int main(int argc, char* argv[])
 {
-	int i, res, nresources;
+	int i, k, res, nresources;
 	rtapp_resource_t *rdata;
 	static cpu_set_t orig_set;
 	struct stat sb;
@@ -1597,6 +1644,20 @@ int main(int argc, char* argv[])
 	/* Sync timer resources with start time */
 	clock_gettime(CLOCK_MONOTONIC, &t_start);
 
+    	/* Setup core scheduling */
+        if (opts.core_scheduling_families_count == -1) {
+            for (k = 0; k < opts.num_tasks; k++) {
+                if (opts.threads_data[k].core_scheduling_family > opts.core_scheduling_families_count) {
+                    opts.core_scheduling_families_count = opts.threads_data[k].core_scheduling_family;
+                }
+            }
+        }
+        core_scheduling_first_threads = malloc(sizeof (pid_t) * opts.core_scheduling_families_count);
+    	for (i = 0; i < opts.core_scheduling_families_count; i++) {
+        	core_scheduling_first_threads[i] = 0;
+    	}
+    	pthread_mutex_init(&core_scheduling_mutex, NULL);
+
 	/* Start the use case */
 	int ind = 0;
 	for (i = 0; i < opts.num_tasks; i++) {
@@ -1620,6 +1681,14 @@ int main(int argc, char* argv[])
 			goto exit_err;
 		}
 
+        	if((tdata_orig->core_scheduling_family > 0 && 
+		   tdata_orig->core_scheduling_family > opts.core_scheduling_families_count) || 
+		   tdata_orig->core_scheduling_family < 0) {
+            		log_error("Thread core_scheduling_family (%d) bigger then core_scheduling_families_count (%d)", 
+				  tdata_orig->core_scheduling_family, opts.core_scheduling_families_count);
+            		goto exit_err;
+        	}
+
 		for (j = 0; j < tdata_orig->num_instances; j++) {
 			int ret = create_thread(tdata_orig, ind++, 0, 0);
 			if (ret) {

src/rt-app_parse_config.c

@@ -1083,7 +1083,10 @@ parse_task_data(char *name, struct json_object *obj, int index,
 	data->forked = 0;
 	data->num_instances = get_int_value_from(obj, "instance", TRUE, 1);
 
-	/* Get phases */
+    	/* Get core scheduling cookie if set */
+    	data->core_scheduling_family = get_int_value_from(obj, "core_scheduling_family", TRUE, 0);
+
+    	/* Get phases */
 	phases_obj = get_in_object(obj, "phases", TRUE);
 	if (phases_obj) {
 		/* used in the foreach macro */
@@ -1211,6 +1214,8 @@ parse_global(struct json_object *global, rtapp_options_t *opts)
 	}
 
 	opts->duration = get_int_value_from(global, "duration", TRUE, -1);
+    	opts->core_scheduling_families_count = get_int_value_from(global, "core_scheduling_families_count", 
+								  TRUE, -1);
 	opts->gnuplot = get_bool_value_from(global, "gnuplot", TRUE, 0);
 	policy = get_string_value_from(global, "default_policy",
 				       TRUE, "SCHED_OTHER");

src/rt-app_types.h

@@ -242,6 +242,8 @@ typedef struct _thread_data_t {
 
 	rtapp_resources_t *local_resources;
 	rtapp_resources_t **global_resources;
+
+    	int core_scheduling_family;
 } thread_data_t;
 
 typedef struct _pthread_data_t {
@@ -289,6 +291,8 @@ typedef struct _rtapp_options_t {
 	char *io_device;
 
 	int cumulative_slack;
+
+    	int core_scheduling_families_count;
 } rtapp_options_t;
 
 typedef struct _timing_point_t {